Chevrolet Cars & Trucks - Page 6 - Recent Questions, Troubleshooting & Support

DUring those periods when it doesn't start, does the security light flash? If so, there's a trouble code stored. Also, GM has issued a service bulletin advising you to remove all other electronic devices from the vehicle before starting anti-theft diagnosis. That means removing phone charges, dash cams, even extra transpoder keys from your key ring.

Also, BTW, thanks for not telling us the year, make, model. we know it's a national security secret, but it help technicians to know what vehicle you're asking about.

2008 Chevrolet... | Answered on Nov 10, 2019

On my 04 Grand caravan,the E G R tube went through a pipe about the size of a quarter to the valve should have a rubber grommet in it

Chevrolet... | Answered on Nov 09, 2019

You should just be able to take out the module - just wire directly from the power source, though some controls for all axis functions and you should be good to go. The memory module is not really needed for basic operation.

Chevrolet Cars &... | Answered on Nov 09, 2019

Trace wire and voltage back to switch point and restore with new switch point or new power source.

Chevrolet... | Answered on Nov 09, 2019

Use amp meter and determine power draw against fuse size. Something is shorting - but if you can determine how much power is trying to go through you can devise a fix.

2008 Chevrolet... | Answered on Nov 09, 2019

It can only be power feed. Start at the light work backward till your meter power again. Possibly a broken wire on terminal point.

Chevrolet Cars &... | Answered on Nov 09, 2019

You will need to connect to the computer, check the codes and clear them through the computer. Many auto parts stores will do this for free.
If you dont correct the problem, the check engine light will return.

2014 Chevrolet... | Answered on Nov 09, 2019

This year of truck did have issues with rear disc brakes. Quality of pads is extremely critical. Go with the AC Delco pads and rotors to eleviate some of the issue. Make sure that the slide pins are liberally lubricated and move freely or drag will cause excessive heat to occur. Let me know if you need anything else.

2000 Chevrolet... | Answered on Nov 08, 2019


2004 Chevrolet... | Answered on Nov 08, 2019

effc6b21-e0f8-44d7-ac80-cf6873e12630.jpgYou didn't mention for what system (A/C. Cruise Control etc) so this is for the emissions/powertrain managment.

Chevrolet Lumina... | Answered on Nov 06, 2019


Chevrolet Cars &... | Answered on Nov 05, 2019

So, what is your question?

Chevrolet... | Answered on Nov 04, 2019

Does it have spark at the plugs ?

Chevrolet... | Answered on Nov 04, 2019

Could be bad ignition switch or some other type electrical problem . Knowing how this system works on your vehicle is the key . The ignition switch is a low voltage input to the BCM - body control module . Depending on key position the BCM knows what relays to energize and what messages to send over the GMLAN serial data net work , PCM - engine computer . Hooking up a factory or some other type professional scan tool to view ignition switch inputs to the BCM , an checking for BCM DTC'S - diagnostic trouble codes .

Circuit Description
Moving the ignition switch to the START position signals the body control module (BCM) through discrete inputs from the ignition transducer that engine crank has been requested. The BCM verifies that theft is not active and sends a serial data message to the engine control module (ECM)/powertrain control module (PCM) requesting engine start. The ECM/PCM receives a 12-volt signal from the park/neutral position (PNP) switch or clutch pedal start switch notifying that it is safe to start the engine. There is a splice on this circuit in the fuse block-underhood that supplies power for the starter relay coil. The starter relay coil control circuit is then grounded by the ECM/PCM closing the switch in the starter relay suppling 12 volts to the S-terminal of the starter. Ground is supplied through the engine block.

Plus you need to under stand what power modding is , because the BCM is the power mode master . This will sound funny to someone who does not know about automotive electronics .
Serial Data Gateway
The body control module (BCM) in this vehicle functions as a translator between the High and Low speed GMLAN busses. The 2 communication protocols use the BCM to translate communicated serial data messages between the control modules over the 2 serial data busses.
Power Mode Master
This vehicles body control module (BCM) functions as the power mode master (PMM). Refer to Power Mode Description and Operation for a complete description of power mode functions.

Power to many of this vehicle's circuits are controlled by the module that is designated the power mode master (PMM). This vehicle's PMM is the body control module (BCM). The PMM controls which power mode (Run, Accessory, Crank, Retained Accessory Power, or Off) is active.

On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle, the PMM is the body control module (BCM). The PMM receives 3 discrete ignition switch signals to differentiate which power mode will be sent over the Serial Data circuits. The 3-wire Ignition Switch table below illustrates the state of these inputs in correspondence to the ignition switch position:
Relay Controlled Power Mode
The body control module (BCM) uses the discrete ignition switch inputs Off/Run/Crank, Accessory, and ignition 1, to distinguish the correct power mode. The ignition 1 circuit is also routed to the Run/Crank relay for relay controlled power feeds during the appropriate power mode. The BCM, after determining the desired power mode, will activate the appropriate relays for that power mode.

Chevrolet Cobalt... | Answered on Nov 03, 2019

Sounds like the ignition key mechanism has failed. Probably needs replacing. Has anyone been attaching wires to it? If so, they may have mixed up the wiring.

Chevrolet Cobalt... | Answered on Nov 03, 2019

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