Tip & How-To about Chevrolet 1500

Why is my car's CHECK ENGINE LAMP on?

Most vehicals manufactured after 1980 have some type of Check Engine Lamp. The lamp is a telltail signal initiated by the On Board Computer. The Computer recieves input signals from various sensors in the Fuel Management System. These inputs allow the On Board Computer to adjust it's Outputs to coinside with variables which may or not be within it's control. When the On Board Computer detects an input or output which contridicts normal known values, it turns on the Check Engine Lamp. The On Board Computer also sets (records) a fault code in it's memory, which should lead the repair technician to the proper area for diagnosis. Most vehicals with require a scan type tool to access the fault code. After the code is aquired diagnosis can begin.

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1 Answer

the hazard back lights wont quit blinking when car is running even when i pull the fuse on a 2002 buick regal


What fuse are you pulling ?

Hazard Lamps
The hazard warning switch is part of the turn signal switch. The turn signal switch receives battery voltage at all times through the HAZARD SWITCH Fuse. When the hazard switch is placed in the HAZARD position, battery voltage is applied to the hazard lamp/turn signal lamp flasher. The hazard lamp/turn signal lamp flasher sends a turn signal flasher signal to the turn signal switch. The turn signal switch provides all of the turn lamps and turn indicators with the turn signal flasher signal, simultaneously flashing them on and off.

Turn Signal Lamps
The front turn signal lamps are made up of the front park/turn signal lamps and rear turn signal lamps. The front turn signal lamps flash with the rear turn signal lamps when a turn is initiated using the turn signal/multifunction lever. The turn signals will operate only with the ignition switch in the RUN position and will not operate during hazard flasher operation.
When the ignition is turned to the RUN position, battery voltage is supplied to the TURN SIGNAL Fuse. Battery voltage is then applied through the turn signal fuse circuit to the turn signal switch. When the turn signal switch is placed in the LH or RH position, voltage is supplied to the hazard lamp/turn signal lamp flasher. The hazard lamp/turn signal lamp flasher supplies a turn signal flasher signal to the turn signal switch. With the turn signal switch in the LH or RH position the corresponding turn signal indicator, rear turn signal, and front turn signal receive the turn signal switch signal and will flash. The front turn signals receive the turn signal switch signal from the turn signal switch via the BCM. The turn lamps are permanently grounded.

Replace the turn signal switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt.

Feb 11, 2017 | Buick Cars & Trucks

1 Answer

no turning signals


Turn Signal Lamps
The turn signal lamps are made up of the front park/turn signal lamps and rear turn signal lamps. The front turn signal lamps flash with the rear turn signal lamps when a turn is initiated using the turn signal/multifunction lever. The turn signals will operate only with the ignition switch in the RUN position and will not operate during hazard flasher operation.
When the ignition is turned to the RUN position, battery voltage is supplied to the TURN SIGNAL, CORN LPS Fuse. Battery voltage is then applied through the TURN SIGNAL, CORN LPS fuse circuit to the hazard warning switch. The hazard switch supplies a turn signal flasher signal to the turn signal switch. With the turn signal switch in the LH or RH position the corresponding turn signal indicator, rear turn signal, and front turn signal receive the turn signal switch signal and will flash. The front turn signals receive the turn signal switch signal from the turn signal switch via the body control module (BCM) . The front turn lamps are grounded at G101. The rear turn lamps are grounded at G301 and G302.
Turn Signal Lamps and/or Indicators Inoperative

2

  1. Turn the ignition switch to the ON position.
  2. Place the turn signal switch in the LH and RH on position.
Do the turn signals operate properly?
Go to Testing for Intermittent Conditions and Poor Connections yes
Go to Step 3 no

3

Are all of the turn signal lamps and indicators inoperative?
Go to Step 5 yes
Go to Step 4 no

4

Are only the turn signal indicators inoperative?
Go to Step 16 yes
Go to Step 9 no

5

Check the TURN SIGNALS CORN LPS fuse for an open.
Is the TURN SIGNALS CORN LPS fuse open?
Go to Step 25 yes
Go to Step 6 no

6

  1. Disconnect the hazard switch.
  2. Turn the ignition to the ON position, with the engine OFF.
  3. Connect a test lamp between the ignition positive 1 voltage circuit of the hazard switch and a good ground.
Does the test lamp illuminate?
Go to Step 7 yes
Go to Step 27 no

7

Connect a test lamp between the ignition 1 positive supply voltage circuit of the hazard switch and the ground circuit of the hazard switch .
Does the test lamp illuminate?
Go to Step 8 yes
Go to Step 23 no

8

  1. Install a fused jumper between the ignition 1 positive voltage circuit of the hazard switch and the turn signal flasher signal circuit of the hazard switch.
  2. Place the turn signal switch in the RH on position and the LH on position.
Do the turn signal lamps illuminate?
Go to Step 17 yes
Go to Step 15 no

9

Is a front turn signal inoperative?
Go to Step 10 yes
Go to Step 13 no

10

  1. Turn the ignition switch to the ON position.
  2. Disconnect the inoperative front turn signal lamp.
  3. Connect a test lamp between the supply voltage circuit of the inoperative front turn signal lamp and a good ground.
  4. Place the turn signal switch in the appropriate ON position.
Does the test lamp flash ON and OFF?
Go to Step 14 yes
Go to Step 11 no

11

  1. Disconnect the body control module (BCM) connector.
  2. Connect a test lamp between ground and the front turn signal switch signal circuit of the BCM.
  3. Place the turn signal switch in the appropriate ON position.
Does the test lamp flash ON and OFF?
Go to Step 12
Go to Step 22

12

Test for an open or for a high resistance in the supply voltage circuit of the inoperative front turn signal lamp. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?
Go to Step 34
Go to Step 21

13

  1. Turn the ignition switch to the ON position.
  2. Disconnect the inoperative rear turn signal lamp.
  3. Connect a test lamp between the supply voltage circuit of the inoperative turn signal lamp and a good ground.
  4. Place the turn signal switch in the appropriate ON position.
Does the test lamp flash ON and OFF?
Go to Step 14
Go to Step 28

14

Connect a test lamp between the ground circuit of the inoperative turn signal lamp and supply voltage circuit of the inoperative turn signal lamp.
Does the test lamp illuminate?
Go to Step 20
Go to Step 26

15

Test for an open or high resistance in the turn signal flasher signal circuit. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?
Go to Step 34
Go to Step 18

16

  1. Turn OFF the ignition.
  2. Disconnect the instrument panel cluster (IPC).
  3. Connect a test lamp between the supply voltage circuit of the inoperative turn signal indicator and the instrument panel cluster (IPC) ground circuit.
  4. Place the turn signal switch in the appropriate ON position.
Does the test lamp flash ON and OFF?
Go to Step 19
Go to Step 24

17

Inspect for poor connections at the harness connector of the hazard switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
Go to Step 34
Go to Step 30

18

Inspect for poor connections at the turn signal switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
Go to Step 34
Go to Step 29

19

Inspect for poor connections at the instrument panel cluster (IPC). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
Go to Step 34
Go to Step 31

20

Inspect for poor connections at the inoperative turn signal lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
Go to Step 34
Go to Step 32

Sep 05, 2015 | 2001 Oldsmobile Intrigue

1 Answer

car stalls after turn or idle


Q; Is your service engine lamp on? This vehical has a power steering pressure switch,witch helps your engine maintane idle at parking lot monuvers. its next to your power steering pump.you can check if it works by starting your engine and let it warm up. then without tuching your gas pedal turn your steering wheel slowly , the engine should maintane its idle. if this works and your service eng. soon is not on then try cleaning your throttle plate. A dirty throttle is alot of stalling causes with all vehicals.

Jan 18, 2012 | 2000 Ford Focus

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.
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)

Nov 19, 2011 | 1994 Jeep Grand Cherokee

1 Answer

What does it mean if the malfunction light on a 2001 Dodge Neon remains lite when engine is running?


Where have you been since 1980,some 32 model years?

The MIL Lamp,Check Light or any dash light
is an OBD2 (On-Board-Diagnostic) light indicating
a possible vehicle system malfunction

Check for codes --- within a couple of days
Diagnose system--soon
Repair or stop using the vehicle, if repairs can
not be made in a week or so

Jul 23, 2011 | 2001 Dodge Neon

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