Computer Codes What Does Battery voltage sense input below target charging during engine operation. Also, no significant change detected in battery voltage during active test of generator output circuit Mean?

Could be the alternator , you can have it checked free at most auto part stores . Have them check for DTC'S diagnostic trouble codes as well . The charging system is controlled by the PCM - engine computer , if it see's a problem it will set a DTC and have the insturment cluster turn on the battery light. Plus the way the radio is acting ,it's loosing power .
DTC B1327
The body control module (BCM) determines battery positive voltage through the 10A Cluster/BCM fuse input. The BCM then sends a class 2 serial data message containing the measured battery voltage value. The vehicle control interface module (VCIM/OnStar®) module monitors this class 2 message to determine vehicle voltage.
DTC P0560
The PCM monitors the system voltage to make sure that the voltage stays within the proper range. Damage to components, and incorrect data input can occur when the voltage is out of range. The PCM monitors the system voltage over an extended length of time. If the PCM detects a system voltage outside an expected range for the calibrated length of time, DTC P0560 will set.
DTC P0620
The powertrain control module (PCM) uses the generator turn on signal circuit to control the generator. A high side driver within the PCM allows the PCM to turn the generator ON and OFF. When Generator operation is desired, the PCM sends a 5 volt signal to the voltage regulator via the generator turn on signal circuit. This causes the voltage regulator to begin controlling the generator field circuit. Once the Generator is enabled by the PCM, the voltage regulator controls generator output independently of the PCM by monitoring the battery positive voltage sense circuit. Under certain operating conditions, the PCM can turn Off the generator by turning OFF the 5 volt signal on the generator turn on signal circuit. The PCM has fault detection circuitry which monitors the state of the generator turn on signal circuit. If the fault detection circuit senses a voltage other than what is expected, this DTC will set. The voltage regulator also contains fault detection circuitry. If the regulator detects a problem, the regulator will ground the generator turn on signal circuit, pulling the voltage low. This also causes the PCM to set the DTC.
When this DTC sets, the PCM sends a class 2 serial data message to the IPC illuminating the Charge indicator lamp.

Or it may be more wise to have a qualified repair shop check it out .

Under hood,passenger side mounted on the firewall,but ...
Could be something else ,crank sensor or cam,or ign.rotor ect.
The module like 3 hundred bucks.Try this ,turn the key
on-off-on-off-on( without out hitting the starter) the check
engine light should begin to flash.
Here is a code list,may narrow down the problem.
Diagnostic Trouble Code Descriptions and service hints. Fault Code DRB Display Code Description. Service hints. 11 No Crank reference signal at PCM No Distributor reference signal detected during engine cranking. Check the circuit between the distributor and PCM. 12 Battery Disconnect Direct Battery input to PCM disconnected within last 50 ignition key-on cycles. Normal if battery has been disconnected, otherwise check battery power and ground connections. 13** No change in MAP from start to run No difference seen between the engine MAP reading and the barometric (atmospheric) pressure reading at startup. Indicates a problem with the MAP sensor vacuum system. 14** MAP sensor voltage too low or too high MAP sensor voltage output is outside the acceptable range. 15** No Vehicle speed sensor signal No signal received from the vehicle speed sensor during road load operation. 17* Engine is cold too long Engine temperature too high or too low while traveling. Check coolant level, radiator cap, temperature sensor, and thermostat. 21** O2S Stays at center O2S shorted to voltage O2 sensor does not detect rich or lean condition, or O2 sensor input voltage too high. DRB will indicate which side with dual sensors. The O2 sensor signal should fluctuate under normal conditions. 22** ECT sensor voltage too high or too low Engine Coolant temperature sensor input out of normal range. Check engine temperature sensor. 23** Intake air temp sensor voltage too high or low Intake air manifold temperature sensor is out of range. Check sensor. 24** Throttle position sensor voltage too high or low TPS sensor is out of normal range. 25** Idle air control motor circuits A short is detected in one or more of the idle air motor circuits. 27* Injector # control circuit Injector number # output driver circuit does not respond to the control signal. Check the affected circuit. 31** EVAP Solenoid Circuit Short or open in the EVAP solenoid circuit. Check for loose, broken, or shorted wire in the charcoal canister purge solenoid wiring and connectors. 32** EGR Solenoid circuit Short or open in the EGR solenoid circuit. Check for loose, broken, or shorted wire in the EGR valve wiring and connectors. Possible air fuel ratio imbalance not detected during diagnosis. 33* AC clutch relay circuit Short or open in the AC clutch circuit. 34* Speed control circuit or speed control switch always low or high An open or short in the speed control vacuum or vent circuits. Speed control switch input above or below normal range. 35 Radiator Fan low speed relay circuit Open or short in the radiator fan relay wiring. 37** Torque converter clutch solenoid CKT or Trans temp sensor too high or low Open or short in CKT wiring or connectors. Voltage out of range at transmission temperature sensor input. See NOTE #1 below 41** Generator field not switching properly Open or short in the generator (alternator) field control (regulator) circuit. This indicates a problem with the charging circuit and the fault is set when the battery voltage from the ASD relay falls below 11.75 volts. Wiring, connectors, fuses, and the ASD relay should be checked. A shorted battery cell can also trigger this fault. 42* Auto shutdown relay circuit Open or short in the ASD relay wiring or connectors. 43** Ignition coil circuit # Open or short in number # coil circuit. Indicates that the ignition coil's peak primary circuit current is not achieved with the maximum dwell time. 44* Battery temp sensor volts out of range An open or short in the engine coolant temperature sensor circuit or a problem in the PCM's battery temperature circuit. 45* Trans OD solenoid circuit Transmission OD solenoid circuit failure. Open or short in the transmission overdrive solenoid circuit. 46** Charging system voltage too high Battery voltage sense input above target charging voltage during engine operation. Computer is indicating that the battery voltage is not being regulated. 47** Charging system voltage too low Battery voltage sense input above target charging voltage during engine operation. Also, no significant change in battery voltage was detected during a test of the generator output. 51** System lean L-Idle Adap at rich limit or lean R-Idle Adap at rich limit O2 sensor signal indicates lean air/fuel ratio during engine operation. The computer ran the mixture to the rich limit of programming, but the O2 sensor still indicated a lean condition. L or R indicate left or right side O2 sensor. Fuel pressure problems can lean the mixture and set this fault. 52** System rich L-Idle Adap at lean limit or rich R-Idle Adap at lean limit O2 sensor signal indicates rich air/fuel ratio during engine operation. The computer ran the mixture to the lean limit of programming, but the O2 sensor still indicated a rich condition. L or R indicate left or right side O2 sensor. Faulty ignition components, high or low fuel pressure, or leaking injectors can set this fault. 53* Internal PCM failure or PCM SPI comm failure An internal PCM failure or PCM communications failure has been detected. 54* No cam sync signal at PCM No fuel sync (camshaft signal) detected during engine crank. No camshaft position sensor signal was received from the distributor. Problem with the distributor synchronization circuit. 55 N/A End of message code. A DTC 55 is used to end all DTC messages. This code does not show on the DRB tool and indicates a completion of the stored codes on the Malfunction Indicator Lamp (check engine lamp). 62* PCM failure SRI miles not stored Unsuccessful attempt to update Service Reminder Indicator miles in the PCM EEPROM (memory). 63* PCM Failure EEPROM write denied Unsuccessful attempt to write and EEPROM location by the PCM. Controller failure, check the PCM. This code can be set when attempting an unauthorized reprogram of the PCM. 71** Aux 5V signal voltage low The auxiliary 5 volt supply output voltage is low. The 5 volt output signal is not reaching the required voltage level. 72** Catalytic Converter efficiency failure The catalytic converter is not converting emissions in the proper ratio.

CODE 11 No distributor referene signal detected during engine cranking....Check circuit between the distributer and the pcm.

CODE 12 Problem with battery connection.Direct battery input to pcm disconnected within the last 50 ignition key-on cycles.

CODE 13** Indicates a problem with map sensor vacuum system.

CODE 14** map sensor voltage to high or to low.

CODE 15** Problem with vehicle speed sensor signal.No vss signal detected during road load conditions.

CODE 17 Engine is cold to long.Engine coolant temp stays below normal operating temp(check thermostat).

CODE 21** Problem with oxygen sensor signal circuit.Sensor voltage to computer not fluctuating.

CODE 22** Coolant sensor voltage to high or to low.Test coolant temp sensor.

CODE 23** Indicates that the air temp sensor input is below the minimum acceptable voltage or sensor input is above the acceptable voltage.

CODE 24** Throttle position sensor voltage to high or low.Test the tps.

CODE 25** Idle air control (IAC) valve circuits.A shorted condition is detected in one or more of the IAC valve circuits.Or a vacuum leak has been detected.

CODE 27 One of the injector control circuit output drivers does not respond properly to the control signal.Check the circuits.

CODE 31** Problem with canister purge solenoid circuit.

CODE 32** An open or shorted condition detected in the EGR solenoid circuit.Possible air/fuel ratio imbalance not detected during diagnosis.

CODE 33 Air conditioning clutch relay circuit.An open or shorted condition in the compressor clutch relay circuit.

CODE 34 Open or shorted condition in the speed control vacuum or vent solenoid circuits.

CODE 35 Open or shorted condition detected in the radiator fan low speed relay circuit.

CODE 37** Open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit.

CODE 41** Problem with charging system.An open or shorted condition detected in the generator Field control circuit.

CODE 42 Fuel pump relay or auto shutdown relay (ASD) control circuit indicates an open or shorted condition.

CODE 43** Multiple cylinder misfire detected.Peak primary circuit current not achieved with the maximum dwell time.

CODE 44 Battery temperature sensor volts malfunction.Problem with the battery temperature voltage circuit in the pcm.

CODE 46** Charging system volts to high>Computer indicates that the battery voltage is not properly regulated.

CODE 47** Charging system voltage to low.Battery voltage sense input below target charging voltage during engine operation and no significant change in voltage detected during active test or alternator output.

CODE 51** Oxygen sensor signal input indicates lean air/fuel ratio condition during operation.

CODE 52** Oxygen sensor signal input indicates rich air/fuel ratio during engine operation.

CODE 53** internal pcm failure detected.

CODE 54** No camshaft position sensor signal from distributer.Problem with the distributer synchronization circuit.

CODE 55 Completion of fault code display on check engine lamp.this is end of message code.

CODE 62 Unsuccessful attempt to update EMR mileage in the controller EEPROM.

CODE 63** Controller failure.EEPROM write denied.Check the PCM

Almost sounds like an injector heat-soak issue... However I'm wired on coffee and Monster at the moment. By not starting for a few days, do you try to start it several times in the interim, or do you just not touch it out of frustration for a few days? You should be able to check for heat-soak the next time it won't start after a drive by pouring a bottle of cool water over the injectors and down the fuel rail. Should cool off the injectors so they work properly again.

Have you checked to see if there are any codes coming from computer? With the key in the ignition, turn it from off to on three times (not all the way to start, ie crank the motor). So you go on-off-on-off-on-off then back to on and leave it there. The check engine light will flash a specific sequence. It may be handy to have a piece of paper in case there's multiple codes given. Basically what you do is count the flashes. They'll come in two-digit sequences, with the digits separated by a small pause. If there are multiple codes, they will be separated by a longer pause. So flash-flash-pause-flash-flash-flash paauuusssee flash-flash-flash-pause-flash-flash-flash would be a 23 and 33 respectively, if that makes sense.

This may help you with trouble-shooting, especially if the computer does give you some codes. Don't worry about Code 12 and Code 55, as 12 is battery/power disconnected within last 50 engine starts (or something like that), and 55 is end of message (ie, no more codes).

Edit**
Codes for your year are:
Code 88-Display used for start of test.
Code 11-Camshaft signal or Ignition signal-no reference signal detected during engine cranking.
Code 12-Memory to controller has been cleared within 50-l00 engine starts.
Code 13-MAP sensor pneumatic signal-no variation in MAP sensor signal is detected or no difference is recognized between the engine MAP reading and the stored barometric pressure reading..
Code 14-MAP voltage too high or too low.
Code 15-Vehicle speed sensor signal-no distance sensor signal detected during road load conditions.
Code 16-Knock sensor circuit-Open or short has been detected in the knock sensor circuit.
Code 16-Battery input sensor-battery voltage sensor input below 4 volts with engine running.
Code 17-Low engine temperature-engine coolant temperature remains below normal operating temperature during vehicle travel; possible thermostat problem.
Code 21-Oxygen sensor signal-neither rich or lean condition is detected from the oxygen sensor input.
Code 22-Coolant voltage low-coolant temperature sensor input below the minimum acceptable voltage/Coolant voltage high-coolant temperature sensor input above the maximum acceptable voltage.
Code 23-Air Charge or Throttle Body temperature voltage HIGH/LOW-charge air temperature sensor input is above or below the acceptable voltage limits.
Code 24-Throttle Position sensor voltage high or low.
Code 25-Automatic Idle Speed (AIS) motor driver circuit-short or open detected in 1 or more of the AIS control circuits.
Code 26-Injectors No. 1, 2, or 3 peak current not reached, high resistance in circuit.
Code 27 -Injector control circuit-bank output driver stage does not respond properly to the control signal.
Code 27-Injectors No. 1, 2, or 3 control circuit and peak current not reached.
Code 31-Purge solenoid circuit-open or short detected in the purge solenoid circuit.
Code 32-Exhaust Gas Recirculation (EGR) solenoid circuit-open or short detected in the EGR solenoid circuit/EGR system failure-required change in fuel/air ratio not detected during diagnostic test.
Code 33-Air conditioner clutch relay circuit-open or short detected in the air conditioner clutch relay circuit. If vehicle doesn't have air conditioning ignore this code.
Code 34-Speed control servo solenoids or MUX speed control circuit HIGH/LOW-open or short detected in the vacuum or vent solenoid circuits or speed control switch input above or below allowable voltage.
Code 35-Radiator fan control relay circuit-open or short detected in the radiator fan relay circuit.
Code 35-Idle switch shorted-switch input shorted to ground-some 1993 vehicles.
Code 37-Part Throttle Unlock (PTU) circuit for torque converter clutch-open or short detected in the torque converter part throttle unlock solenoid circuit.
Code 37-Baro Reed Solenoid-solenoid does not turn off when it should.
Code 37-Shift indicator circuit (manual transaxle).
Code 41-Charging system circuit-output driver stage for generator field does not respond properly to the voltage regulator control signal.
Code 42-Fuel pump or no Autoshut-down (ASD) relay voltage sense at controller.
Code 43-Ignition control circuit-peak primary circuit current not respond properly with maximum dwell time.
Code 43-Ignition coil #1, 2, or 3 primary circuits-peak primary was not achieved within the maximum allowable dwell time.
Code 44-Battery temperature voltage-problem exists in the PCM battery temperature circuit or there is an open or short in the engine coolant temperature circuit.
Code 44-Fused J2 circuit in not present in the logic board; used on the single engine module controller system.
Code 44-Overdrive solenoid circuit-open or short in overdrive solenoid circuit.
Code 46-Battery voltage too high-battery voltage sense input above target charging voltage during engine operation.
Code 47-Battery voltage too low-battery voltage sense input below target charging voltage.
Code 51-Air/fuel at limit-oxygen sensor signal input indicates LEAN air/fuel ratio condition during engine operation.
Code 52-Air/fuel at limit-oxygen sensor signal input indicates RICH air/fuel ratio condition during engine operation.
Code 53-Internal controller failure-internal engine controller fault condition detected during self test.
Code 54-Camshaft or (distributor sync.) reference circuit-No camshaft position sensor signal detected during engine rotation.
Code 55-End of message.
Code 61-Baro read solenoid-open or short detected in the baro read solenoid circuit.
Code 62-EMR mileage not stored-unsuccessful attempt to update EMR mileage in the controller EEPROM.
Code 63-EEPROM write denied-unsuccessful attempt to write to an EEPROM location by the controller.
Code 64-Flex fuel sensor- Flex fuel sensor signal out of range-(new in 1993)-CNG Temperature voltage out of range-CN gas pressure out of range.
Code 66-No CCD messages or no BODY CCD messages or no EATX CCD messages-messages from the CCD bus or the BODY CCD or the EATX CCD were not received by the PCM.
Code 76-Ballast bypass relay-open or short in fuel pump relay circuit.
Code 77-Speed control relay-an open or short has been detected in the speed control relay.
Code 88-Display used for start of test.
Code Error-Fault code error-Unrecognized fault ID received by DRBII.

Please let me know.

before 1996 they use onboard diagnosis system for jeep.

when you turn on key you need to count check engine light blinks.

here are codes taken from internet.

11* No crank reference signal detected during engine cranking.
12* Direct battery input to PCM was disconnected within the last 50 key-on cycles.
13** No difference recognized between the engine MAP reading and the barometric (atmosphereic) pressure reading at start-up
14** MAP sensor input below minimum acceptable voltage.
or
MAP sensor input above maximum acceptable voltage.
15** No vehicle distance (speed) sensor signal detected during road load conditions.
17* Engine coolant temperature remains below normal operating temperatures during vehicle travel (thermostat).
21** Neither rich nor lean condition detected from the oxygen sensor input.
or
Oxygen sensor input voltage maintained above the normal operating range.
22** Engine coolant temperature sensor input above maximum acceptable voltage.
or
Engine coolant temperature sensor input below minimum acceptable voltage.
23** Intake manifold air temperature sensor input above maximum acceptable voltage.
or
Intake manifold air temperature sensor input below minimum acceptable voltage.
24** Throttle position sensor input above maximum acceptable voltage.
or
Throttle position sensor input below minimum acceptable voltage.
25** A shorted condition detected in one or more of the idle air control motor circuits.
27* Injector #1 output driver does not respond properly to the control signal.
or
Injector #2 output driver does not respond properly to the control signal.
or
Injector #3 output driver does not respond properly to the control signal.
or
Injector #4 output driver does not respond properly to the control signal.
or
Injector #5 output driver does not respond properly to the control signal.
or
Injector #6 output driver does not respond properly to the control signal.
33* An open or shorted condition detected in the A/C clutch relay circuit.
34* An open or shorted condition detected in the speed control vacuum or vent solenoid circuits.
or
Speed control switch input below the minimum acceptable voltage.
or
Speed control switch input above the maximum acceptable voltage.
35* An open or shorted condition detected in the radiator fan relay circuit.
41* An open or shorted condition detected in the generator field control circuit.
42* An open or shorted condition detected in the auto shutdown relay circuit.
44* An open or shorted condition exists in the engine coolant temperature sensor circuit or a problem exists in the PCM's battery temperature voltage circuit.
46** Battery voltage sense input above target charging voltage during engine operation.
47** Battery voltage sense input below target charging voltage during engine operation. Also, no significant change detected in battery voltage during active test of generator output.
51** Oxygen sensor signal input indicates lean air/fuel ratio condition during engine operation.
52** Oxygen sensor signal input indicates rich air/fuel ratio condition during engine operation.
53* PCM internal fault condition detected.
54* No fuel sync (camshaft signal) detected during engine cranking.
55* Completion of diagnostic trouble code display on the malfunction indicator lamp (check engine lamp).
62* Unsuccessful attempt to update SRI (service reminder indicator) miles in the PCM EEPROM.
63* Unsuccessful attempt to write to an EEPROM location by the PCM.

* - Check engine lamp will not illuminate at all times if this code was recorded. Cycle ignition key as described and observe code flashed by check engine lamp.

** - Check engine lamp will illuminate during engine operation if this code was recorded.

PCM = Powertrain Control Module (the engine computer)
MAP = Manifold Absolute Pressure (the sensor that measures how hard the engine is sucking air through the intake manifold
EEPROM = Electrically Erasable Programmable Read Only Memory (a type of computer chip used inside the PCM)

Yes here is that list.
Chrysler products COMMON CODES OBD1 (vehicles made before 1995)
Part 1: Chrysler Domestic vehicles
CODES/Meaning
88 display used for start or test
11 camshaft signal or ignition signal, no reference signal during cranking
12 memory to controller has been cleared within 50-100 engine starts
13 map sensor not detecting any change during test
14 map voltage too high or too low
15 vehicle speed sensor, no signal detected
16 knock sensor circuit. open or short detected
17 low engine temperature, possible thermostat fault
21 oxygen sensor signal, neither rich or lean detected
22 coolant sensor voltage low
23 air charge voltage high/low detected
24 throttle positioner sensor voltage high/low
25 automatic idle speed motor driver circuit, short or open detected
26 injectors 1,2,3 peak current not reached
27 injector control circuit does not respond to control signal
31 purge solenoid circuit, open or short detected
32 egr solenoid circuit, open or short detected
33 a/c clutch relay circuit, open or short detected
34 speed control servo solenoid, open or short detected
35 radiator fan control relay circuit, open or short detected
36 wastegate solenoid, open or short detected
37 part throttle unlock(PTU) circuit, open or short detected
41 charging system circuit not responding to control signal
42 fuel pump or auto shutdown (ASD) relay voltage sensed at controller
43 ignition control circuit not responding
44 battery temperature voltage circuit problem
45 turbo boost limit exceeded-map sensor detects overboost
46 battery voltage too high
47 battery voltage too low
51 air/fuel at limit
52 logic module fault
53 internal controller failure
54 camshaft reference circuit not detected
55 end of message
61 baro read solenoid, open or short detected
62 emr mileage not stored
63 eeprom write denied
64 flex fuel sensor signal out of range
65 manifold tuning valve, open or short detected
66 no ccd messages
76 ballast bypass relay, open or short detected
77 speed control relay, open or short detected

Code 47 means Battery voltage sense input below target charging voltage during engine operation.
1st Thing i would check is the battery, to make sure it has a full charge and full amount of cold cranking amps and make sure all connection are clean and tight.
2ND If you have a voltmeter check and see if alternator is putting out enough volts should be close to 14.5 volts. If you have no way to check them most auto parts store will check them for free.
If i can help anymore please re post . Thanks dodge tec

Not absolutely sure on the codes given. You can buy a Haynes or Chilton Manual at most auto parts stores for the vehilce. $20-$30. For a 1984-1995 Caravan the following codes are:
Code 12 = Number of key-ons since last fault or since fault(s) were erased. Battery to controller disconnected within last 50 to 100 ign key on's.
Code 24 = Throttle Position Sensor low voltage.
Code 34 = Speed control solenoid circuit. An open or shorted condition in the speed control vent or vacuum solenoid circuits,
Code 47 = Charging System too low. Battery voltage inut below target charging during engine operations. And no significant change in voltage during active test of altenator output.
Code 53 = Internal controller failure. Internal engine controller fault condition detected.
Code 55 = Completion of Codes.
Code 51 & Code 52 = O2 Sensor problems.
Buy the book to verify and compare.

What problems are you having currently/
12 is battery has been disconnected recently
42 is fuel pump relay circuit
45 is turbo boost, but I suspect your is non-turbo.
46 is usually charging system related.

Hope this is helpful, Ian

CHARGING
DESCRIPTION - CHARGING SYSTEM
The charging system consists of:
† Generator
† Decoupler Pulley (If equipped)
† Electronic Voltage Regulator (EVR) circuitry
within the Powertrain Control Module (PCM)
† Ignition switch (refer to the Ignition System section
for information)
† Battery (refer to the Battery section for information)
† Battery temperature sensor
† Voltmeter (refer to the Instrument Cluster section
for information)
† Wiring harness and connections (refer to the
Wiring section for information)
† Accessory drive belt (refer to the Cooling section
for more information)
OPERATION - CHARGING SYSTEM
The charging system is turned on and off with the
ignition switch. The system is on when the engine is
running and the ASD relay is energized. When the
ASD relay is on, voltage is supplied to the ASD relay
sense circuit at the PCM. This voltage is connected
through the PCM and supplied to one of the generator
field terminals (Gen. Source +) at the back of the
generator.
The generator is driven by the engine through a
serpentine belt and pulley or decoupler pulley
arrangement.
The amount of DC current produced by the generator
is controlled by the EVR (field control) circuitry
contained within the PCM. This circuitry is connected
in series with the second rotor field terminal
and ground.
A battery temperature sensor is used to sense battery
temperature. This temperature data, along with
data from monitored line voltage, is used by the PCM
to vary the battery charging rate. This is done by
cycling the ground path to control the strength of the
rotor magnetic field. The PCM then compensates and
regulates generator current output accordingly to
maintain system voltage at the targeted system voltage
based on battery temperature.
All vehicles are equipped with On-Board Diagnostics
(OBD). All OBD-sensed systems, including EVR
(field control) circuitry, are monitored by the PCM.
Each monitored circuit is assigned a Diagnostic Trouble
Code (DTC). The PCM will store a DTC in electronic
memory for certain failures it detects. Refer to
On-Board Diagnostics in the Electronic Control Modules(
Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/POWERTRAIN CONTROL
MODULE - DESCRIPTION) section for more DTC
information.
The Check Gauges Lamp (if equipped) monitors:
charging system voltage, engine coolant temperature
and engine oil pressure. If an extreme condition
is indicated, the lamp will be illuminated. This is
done as reminder to check the three gauges. The signal
to activate the lamp is sent via the PCI bus circuits.
The lamp is located on the instrument panel.
Refer to the Instrument Cluster section for additional
information.
VOLTAGE REGULATOR
DESCRIPTION
The Electronic Voltage Regulator (EVR) is not a
separate component. It is actually a voltage regulating
circuit located within the Powertrain Control
Module (PCM). The EVR is not serviced separately. If
replacement is necessary, the PCM must be replaced.
OPERATION
The amount of DC current produced by the generator
is controlled by EVR circuitry contained within
the PCM. This circuitry is connected in series with
the generators second rotor field terminal and its
ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. The
EVR circuitry monitors system line voltage (B+) and
battery temperature or inlet air temperature sensor
(refer to Battery Temperature Sensor or Inlet Air
Temperature Sensor for more information). It then
determines a target charging voltage. If sensed battery
voltage is 325 mv or lower than the target voltage,
the PCM grounds the field winding until sensed
battery volage is 325 mv above target voltage. A circuit
in the PCM cycles the ground side of the generator
field up to 250 times per second (250Hz), but
has the capability to ground the field control wire
100% of the time (full field) to achieve the target
voltage. If the charging rate cannot be monitored
(limp-in), a duty cycle of 25% is used by the PCM in
order to have some generator output. Also refer to
Charging System Operation for additional information.
REMOVAL
The electronic voltage regulator is not a serviced
separately. If replacement is necessary, the PCM
must be replaced.