Question about 1993 Chevrolet C3500

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When I crank the vehicle I have to keep the throttle open I checked the ECU for trouble codes it showed a problem with the MAP sensor voltage too high I replaced the the MAP sensor then trouble code showed voltage too low. What could it be

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Need to check the wiring from map sensor to control module and make sure you got correct map sensor also if o2 sensors are giving incorrect reading can affect this

Posted on Nov 12, 2010


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Got p0748 p0108 code on my 04 honda odyssey. Car sat for about one year. Replaced fuel pump yesterday and it started right up. Can I get info on locations of where sensors are?

PO 748
service the transmission .....check solenoids

- Dirty transmission fluid - Low transmission fluid level - Faulty line pressure solenoid valve 'A' - Line pressure solenoid valve 'A' harness is open or shorted - Line pressure solenoid valve 'A' circuit poor electrical connection

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is the code for a problem with the MAP electrical circuit sensor having too high voltage input to the Engine Control Unit (ECU). This means that the voltage input to the ECU is too high and that it is not in the correct range for proper engine operation to work with inputs from the Mass Air Flow Sensor (MAF) and Throttle Position Switch (TPS). P0108 OBD II Trouble Code Manifold Air Pressure MAP Barometric Pressure...

odyssey map sensor is on the throttle body

Map sensor


Nov 10, 2016 | Honda Cars & Trucks

3 Answers

The throttle body injector goes full on and floods the engine as soon as it starts.

This vehicle has no mass air flow sensor , it uses a MAP sensor for speed density fuel control , My self I would hook up a scan tool an see what the block learn an integrator or showing , this is same as fuel trims on OBD2 vehicles I would also look at the map sensor voltage parameter ! A bad map sensor can cause a lot of fuel to dump into the engine ! Manifold Absolute Pressure MAP Sensors

Apr 19, 2015 | 1992 Geo Metro

2 Answers

Getting trouble code 106. What is solution for correcting this problem. Thank you. 2005 crossfire.

Chrysler codes,. only.


on newer Chysler, cars they have many codes with 106, leaving out the prefix is bad idea.

Like U0102

or C0106?

P0106 is MAP performance failure. (that dont mean replace it)

the puter has no IDEA what is wrong, only that tests failed.

here are the conditions.

When Monitored and Set Condition

  • When Monitored: Engine running for at least 30 seconds and no fault in the throttle valve actuator.

  • Set Condition: Low limit: The Manifold Absolute Pressure (MAP) Sensor reading is below a calculated value when the throttle valve angle is greater than 80F for approximately 5 seconds. High limit: The MAP Sensor reading is greater than a calculated value that is determined by engine speed and throttle valve angle for approximately 5 seconds.

now in gringo or bar stool.

1: the puter brain saw you go near wide open throttle and the

map sensor (vacuum sensor) do not show new zero vacuum.

even a clogged air filter could do this, causing a false high vacuum















then the FSM goes to step by step tests. to find above reasons.

omitted. (too long )

the word low is ambiguous in all FSM.

it can mean, low plenum pressure,

or low vacuum (opposite)

and low voltage, its a pain in the xxx to find this fact out.

the map outputs high voltage for low vacuum (same as high absolute pressure)

the fsm tests are inane.

we check the voltage out of the map

at keyon


and wide open throttle for 1 second. just gun it and watch.

here is what it does.

left side is wide open throttle, idle is 20 inchs. key on is, WOT.

so, what is that

4.5v is keyon

start engine, get about 1.5v

the gun engine, then drop throttel to zero throttle fast

the causes,. huge vacuum about 24 inches, or 1v or less

this is a working MAP. if those tests pass.

the test (OBD2 monitor) fails for about not getting near 4vdc from MAP output pin, DOES THIS HELP?


Jul 07, 2014 | Cars & Trucks

1 Answer

I have a 2008 Suzuki Forenza with 62,000 miles. I am having a hesitating problem. It occurs when proceeding from a stop, but not through the remaining gear changes. It next occurs and you can feel it...

300 is misfire random and might be caused by that limphome mode. The ETC errors always set that mode. RTM read the FSM.
"forced limited power" =failsafe =limphome.
this car has fly by wire. so..... is complex due to that fact.
first do a tuneup. then clean the EGR. (if it leaks , you will get lots of errors and misfiring. at idle. (the freeze frame ,using scan tool shows the parameters that the DTCs failed (last one)
then clean the ETC parts, (idle valves, )
ETC (not ECT) is the engine ,electronic throttle control
the MAP sensor has TSB recall, or service warning for icing up.
no, they didn't fail all at the same time, the ecu only knows
that the tests failed.
here is a crazy example. your intake sucked in Seagull.
and cause may things to read crazy wrong. and you get many DTC.. see? and it's only a seagull,

The way to trouble shoot EFI is to think like an ECU.
case in point:
you step on gas pedal. it's a POT (resistor) the ECU sees you demand acceleration. Pot voltage rises... and...
the ecu then tries to open the throttle.( and electric motor, for fly-by-wire)

1: say it cant? the motor valve in the ETC is sticking.? TV sticks.
it can NOT tell way it is bogging , only that its is not reacting correctly.
so it sets DTCs.. for the ETC. many.

The ECU can not figure out why, it bogs, so guesses.
Is the 60k mile new air filter , still clean? or full of mice nests.?
2: or the EGR leaks. and bogs, off idle stops. same, deal.
the ecu can not tell what caused the bog. but takes wild guesses
the ECU is brick stupid, and only reports failed tests.
3. or the TSB on the MAP , it ices up, fails and bogs, and ECU
sends a barrage of DTCs,

The process of elimination is not a guess. $$$$$$$

it's the technician doing tests. and the 60k mile service top this list.
a full tuneup, clean the egr, and ETC valves. ,spark plugs. filters.
the EGR has a feed back POT. (var. resistor)
ive seen cars that learn the EGR wrong, it sticks open
then learns open, as good. (bad) (EGR software varies wildly by makers and year)
so, i never discount EGR failures, as a source of trouble.'
reset ECU: scan tool , push reset. all DTCs cleared.

What id do is look at all Scan PID's, to see if there are funny reading sensors,
see if you can get DTCs just in Neutral, at idle or gunning the throttle.
Does the ECU hold closed loop, ? at idle
if if race motor say 2500rpm steady does it hold closed loop?
is the TPS responding 1 for 1 with my right foot? scanned.
look at each sensor with the scan tool, for bad readings.
keep in mind , some sensors can be way off and the ECU will never report it, only human eyes on the scan tool screen
can judge right or wrong.
Is LTFT (long term fuel trim) near 0? or at -40 or +40% ???
an iced up MAP will wreck trim, fast.

i guess you never priced the parts?
$$$$$$ for guessing?

a scan tool is $9 , a code reader is near worth less. \
you get a list of numbers, all near useless..... but 300s are the key !
use a real scan tool . SEE with binders off.
find out what DTC throws first. ? and using the freeze frame
see what the conditions were, at the fail. in FF.

the throttle valve is just air supply and is not a AFR, determining device. it only lets in more air.
THe MAP reads the pressure and the ECU uses the MAP to set FUEL rates (speed density system it is)
so The ETC is not a device to cause misfire. (wrong idle yes) or bogging, (ETC motor stalled)
My best guess, (useless) is that the map did ice up, ?
1: map ice
2: egr leaking
3: TV sticking, throttle valve and motor ETC.

best is to find a real ASE mechanic, they don't guess.
Is not drive by wire fun?????
once engines reach this level of complexity, the solutions take harder work. How the ECU reacts to all types of failures vary by maker, and year. (soft/firmware).

Oct 26, 2013 | 2008 Suzuki Forenza

1 Answer

Rough Idle Po120 code

Ok, first things first, have you calibrated your TPS correctly? Being closed throttle voltage of 0 - .459v and WOT (wide open throttle) voltage of 4.98 - 5v if so then make sure your harness and connectors to the TPS and the MAP/MAS sensors are free of corrosion and breaks, and just as important ran in the OE locations not coming into contact with any other components or wiring with in the engine compartment, and that your throttle body/plate is clean and free of gummy oil build up. Now as easy as it can be people tend to write off the part its self being the cause of there problem just because they replaced it, about 2 out of 10 parts bought from a parts store are lemons right out of the box! (AZ) so keep that in mind.
Moving on if that still does not keep the cel light from returning after cleared each time with scanner (KOEO) then it may be time to look at the corresponding sensor to the TPS which is your MAP/MAS. Because the ECU reads the reference signal or voltage returning from these to sensors as a action equal reaction, It can be confused as to which sensor is the colaprete. if you have further questions or need of assistants feel free to send me a message!

Apr 18, 2013 | 1996 Mazda Protege

1 Answer

My 1993 dodge dakota cranks and runs smoothly to any destination, but if i cut off the engine,it will crank but will bot restart until the engine cools(about one hour) any ideas?

Have you run a fualt code test on the systems control mofule? You may have a defective crank sensor or cam sensor, the test will give a code.
For vehicles made after 1996, retrieving the codes of the check engine light in your dash panel is simple. All you need to do is find your diagnostic connector located under the dash by the driver side. You can then hook up a scanner and the codes will be displayed for you. If you don't have any scanner like most drivers, you can bring your vehicle to any local automotive store and they will usually scan the codes FREE for you.

However, for vehicles made on or before 1995, there is only one cheap way to get it: You do it yourself!

On board diagnostic (OBD) was designed on vehicles equipped with electronic fuel injection so you can generally retrieve the codes yourself. No need buying a scanner or running to any parts stores to check the engine light. This system is called obd1 and applies to most vehicles made before 1995 for domestics and 1993 on imports.

Dodge trucks have a diagnostic trouble code retrieval method, Unlike Gm and Ford trucks the Dodge line of trucks has no data port connector to gather codes from.

Instead Dodge has a ignition cycle activation sequence that anyone can active by turning the ignition key on off in rapid succession five times with the cycle ending in the "on" position.

Once this activation has started the check engine light will start to flash. The first set of check engine light flashes will be the first digit of the two number code. After the check engine light pauses for a short time it will start to blink again starting the second digit identification and completing the code's second number. If additional trouble codes are stored in the computer the first digit will begin to flash, and then the second digit. For example: the check engine light flashes four times, pauses and then flashes three more times the code is 43.

The check engine light will flash one and then two meaning the code gathering is over. The system will only flash 12 if there are no codes stored in the computer's memory. To clear codes disconnect the negative battery terminal for 30 seconds and reconnect.

Below are the OBD DTC's for 1995-previous model year EFI-equipped Dodge vehicles.

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 position 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 waste-gate 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 over-boost
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 eprom 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
Import Car Code Definition
1 oxygen sensor
2 crank engine sensor
3 air flow sensor
4 barometric pressure sensor
5 throttle positioner sensor
6 motor position sensor
7 engine coolant temperature sensor
8 no.1 cylinder tdc sensor
12 air flow sensor
13 air temperature sensor
14 throttle positioner sensor
15 sc motor position sensor
21 engine coolant temperature sensor
22 crank angle sensor
23 no.1 cylinder tdc sensor
24 vehicle speed sensor
25 barometric pressure sensor
31 knock sensor
32 manifold pressure sensor
36 ignition timing adjustment signal
39 oxygen sensor
41 injector
42 fuel pump
43 egr
44 ignition coil
52 ignition coil
53 ignition coil
55 iac valve position sensor
59 heated oxygen sensor
61 transaxle control unit cable
62 warm up control valve position sensor

Jun 28, 2012 | 1993 Dodge Dakota

1 Answer

Which codes (OBDI or II) do I use for my 1994 Jeep Grand cherokee laredo 4.0 2wd

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.
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.
Oxygen sensor input voltage maintained above the normal operating range.
22** Engine coolant temperature sensor input above maximum acceptable voltage.
Engine coolant temperature sensor input below minimum acceptable voltage.
23** Intake manifold air temperature sensor input above maximum acceptable voltage.
Intake manifold air temperature sensor input below minimum acceptable voltage.
24** Throttle position sensor input above maximum acceptable voltage.
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.
Injector #2 output driver does not respond properly to the control signal.
Injector #3 output driver does not respond properly to the control signal.
Injector #4 output driver does not respond properly to the control signal.
Injector #5 output driver does not respond properly to the control signal.
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.
Speed control switch input below the minimum acceptable voltage.
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)

Nov 19, 2011 | 1994 Jeep Grand Cherokee

1 Answer

My 2004 GMC Envoy has two trouble code readings of 106 & 128. But the light will come on for a while then it will stay off for a while. The auto parts compny that should me the readings said it could...

Hello there,. Below is the detailed information which you asked for.

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P0106 - MAP/Barometric Pressure Circuit Range/Performance ProblemOBD-II Trouble Code Technical Description

Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem

What does that mean? The Powertrain Control Module (PCM) uses the Manifold Absolute Pressure Sensor (MAP) to monitor engine load. (NOTE: Some vehicles have a Barometric Pressure (BARO) sensor that is integral to the Mass Air Flow (MAF) sensor and do not have a MAP sensor. Other vehicles have a MAF/BARO and a redundant MAP sensor where the MAP sensor functions as a backup input in case of MAF failure.) The PCM supplies a 5 Volt reference signal to the MAP sensor. Usually the PCM also supplies a ground circuit to the MAP sensor as well. As the manifold pressure changes with load, the MAP sensor input informs the PCM. At idle the voltage should be 1 to 1.5 Volts and approximately 4.5 Volts at Wide Open Throttle (WOT). The PCM looks for any change in manifold pressure to be preceded by a change in engine load in the form of changes in throttle angle, engine speed, or Exhaust Gas Recirculation (EGR) flow. If the PCM doesn't see any of these factors change while detecting a rapid change in MAP value, it will set a P0106.
Causes A P0106 could be caused by:

  • Bad MAP sensor
  • Water/dirt intrusion affecting MAP sensor connector
  • Intermittent open in the reference, ground, or signal wire for the MAP sensor
  • Intermittent short in the reference, ground, or signal wire for the MAP sensor
  • Ground problem due to corrosion causing intermittent signal problem
  • A break in the flexible air intake duct between the MAF and the intake manifold
  • Bad PCM (do not assume the PCM is bad until you've exhausted all other possibilities)
Possible Solutions Using a scan tool, watch the MAP sensor value with the key on, engine off. Compare the BARO reading with the MAP reading. They should be roughly equal. The voltage for the MAP sensor should read approx. 4.5 volts. Now start the engine and look for a significant drop in the MAP sensor voltage indicating the MAP sensor is working.
If the MAP reading doesn't change perform the following:
  1. With the Key on, engine off, disconnect the vacuum hose from the MAP sensor. Using a vacuum pump, pull 20 in. of vacuum on the MAP sensor. Does the voltage drop? It should. If it doesn't inspect the MAP sensor vacuum port and vacuum hose to manifold for a restriction of some kind. Repair or replace as necessary.
  2. If there are no restrictions, and the value doesn't change with vacuum, then perform the following: with the Key on and engine off and the MAP sensor unplugged, check for 5 Volts at the reference wire to the MAP sensor connector with a Digital Voltmeter. If there is none, check for reference voltage at the PCM connector. If the reference voltage is present at the PCM connector but not the MAP connector, check for open or short in the reference wire between MAP and PCM and retest.
  3. If reference voltage is present, then check for existing ground at the MAP sensor connector. If it isn't present then repair open/short in the ground circuit.
  4. If ground is present, then replace MAP sensor.
Other MAP sensor trouble codes include P0105, P0107, P0108 and P0109.
P0128 OBD-II Trouble Code Technical Description

Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
What does that mean? This means that the engine's PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 code is to indicate a faulty thermostat. Similar codes: P0125
In determining the engine did not reach a "normal" temperature, it takes into account the length of time the vehicle has been running, the intake air temperature (IAT) sensor reading, the engine coolantmag-glass_10x10.gif temperature (ECT) sensor reading, and the speed of the vehicle.

Causes A code P0128 may mean that one or more of the following has happened:

  • Low engine coolant level
  • Leaking or stuck open thermostat
  • Faulty cooling fan (running too much)
  • Faulty coolant temperature (ECT) sensor
  • Faulty intake air temperature (IAT) sensor
Possible Solutions Past experience indicates that the most likely solution is to replace the thermostat. However here are some suggestions on troubleshooting and repairing a P0128 OBD-II code:
  • Verify coolant strength & level
  • Verify proper cooling fan operation (check if it's running more than it should). Replace if necessary.
  • Verify proper engine coolant temperature (ECT) sensor operation, replace if necessary.
  • Verify proper intake air temperature (IAT) sensor operation, replace if necessary.
  • If the above items check out good, replace the thermostat

Sep 24, 2011 | 2004 GMC Envoy

2 Answers

What are the diag codes for my 2005 sonata, 6 cyc. motor, the check engine lite comes on

Hyundai Specific Trouble Codes Code Description P1100 Manifold Absolute Pressure (MAP) Sensor Malfunction (Open/Short) P1102 Manifold Absolute Pressure (MAP) Sensor Malfunction - Low Voltage P1103 Manifold Absolute Pressure (MAP) Sensor Malfunction - High Voltage P1147 ETS Sub Accel Position Sensor 1 Malfunction P1151 ETS Main Accel Position Sensor 2 Malfunction P1155 ETS Limp Home Valve P1159 Variable Intake Motor Malfunction P1171 Electronic Throttle System Open P1172 Electronic Throttle System Motor Current P1173 Electronic Throttle System Rationality Malfunction P1174 Electronic Throttle System #1 Close Malfunction P1175 Electronic Throttle System #2 Close Malfunction P1176 ETS Motor Open/Short #1 P1176 ETS Motor Open/Short #2 P1178 ETS Motor Battery Voltage Open P1330 Spark Timing Adjust Malfunction P1521 Power Steering Switch Malfunction P1607 Electronic Throttle System Communication Error P1614 Electronic Throttle System Module Malfunction P1632
Go to this page for generic codes that are for all OBD 2 systems

Aug 29, 2008 | Hyundai Sonata Cars & Trucks

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