2002 GMC Envoy - Page 8 - Answered Questions & Fixed issues

The computer on your GMC vehicle generates and stores error codes. An error code does not always mean that something is wrong with your vehicle. Error codes are generated when regular maintenance is required. After you've fixed the broken component or done the required maintenance, you will need to know how to reset the computer and clear all of the error codes so that the check engine or warning light in your GMC vehicle will go out. GMC vehicles use an on-board diagnostic--or OBD-style--port that accepts a special tool called an OBD scan tool. Most auto parts stores have this tool and will perform this task for a nominal fee, and some will do it for free (ie. - Advance Auto, AutoZone, etc.). Hope this helps!

you may have a bad switch ! i could tell you how to test it ,but could be fairly lengthy . do you own a volt meter ? do you know how to use one? should also check for dtc's in transfer case control module ! transfer case shift control switch indicator inoperative - one or more the indicator lamps circuit consist of 5 individual lamps contained inside the mode/range switch assembly. the following lamps are contained inside the respective range button: ?€¢ auto 4wd

?€¢ 2hi

?€¢ 4hi

?€¢ 4lo

each time the ignition is cycled, all 5 mode indicators light simultaneously, as an indicator check to ensure proper operation of the indicators. when the ignition is on, the transfer case shift control module illuminates the indicator lamp that corresponds to the current atc gear position, by providing a ground through a current limiting driver. the transfer case shift control module flashes each indicator lamp after a shift has been requested and continues to flash until the transfer case shift control module completes the shift. a solid state circuit, located inside the switch, supplies ignition voltage to the lamps. the solid state circuit also receives voltage when the headlamp switch is in the parklamp or headlamp position. when the solid state circuit receives voltage from the headlamp switch, the circuit reduces the voltage that is supplied to the indicator lamps, dimming the lamps when the headlamps are on. test description the numbers below refer to the step numbers on the diagnostic table.

1. this step tests the transfer case electrical control of the lamp circuits.
2. this step helps determine module failures.
3. this step tests the affected lamp circuit for an open or high resistance.
4. this step tests the lamp feed circuit for an open or short to ground.

these diagnostic procedures will help you to find and repair automatic transfer case (atc) system malfunctions. this service category also contains information for repairing atc system malfunctions. for best results, use the diagnostic tables and follow the sequence listed below:

1. perform the diagnostic system check - transfer case. all atc diagnostics must begin with the diagnostic system check - transfer case. the diagnostic system check - transfer case determines the following:
?€¢ proper service 4wd indicator operation

?€¢ ability of the transfer case shift control module to communicate through the data link connector (dlc)

?€¢ existence of atc dtcs

2. refer to the diagnostic table as directed by the diagnostic system check - transfer case. the diagnostic tables help enable you to diagnose any atc system malfunction. bypassing these procedures may result in the following:
?€¢ extended diagnostic time

?€¢ incorrect diagnosis

?€¢ incorrect parts replacement

3. repeat the diagnostic system check - transfer case after you perform any repair or diagnostic procedure. this will verify that you correctly performed the repair. this will also ensure that other malfunctions do not exist.

If this has an automatic transmission then the torque converter lock out switch/ solenoid may be bad? It may have not unlocked the torque converter and therefore when you put it in gear the transmission is locked into the torque converter, and will act like an manual transmission when you forget to push in the clutch to stop. You will most likely need to have it scanned, or if you can locate the switch, try unplugging it and see if the vehicle will run? Most are inside the transmission on rear wheel drive GM products. Not a difficult fix, but messy as you have to drain the transmission and drop the pan.

Put power to the motor and see if it hums. Have somebody sit inside and turn key and turn power on to the switch on rear wiper And see if it turns or on the car battery. Power and negative, lets find out if it is the motor or not.

Here you go I hope this video helps you, good luck https://www.youtube.com/watch?v=JIZDsW5jcOo

First thing is to check the fuse. If the fuse is ok,then the shift fork motor might be bad

remove the light sensor module on the top of the dash, it looks like an eye.

well its either before the tank or in the tank or under the hood,i don't know which.get a Haynes repair manual

take it to dealer

look for the fuse at the box (usually on the hood) and pull it off so the ignition won't trigger

On the inside of the truck at the back there is a door looking panel. Kinda behind the tail light but a little further forward. its in there.

check first the wiper motor if althe power is ok then change the bcm

It's under your back seat. See here for picture http://www.ebay.com/itm/like/261068608953?lpid=82 Here is the relearn procedure which you have to perform so the new BCM will recognize your key and start the car: For those vehicles that use a BCM, the BCM can learn the resistance value of the existing key by using the relearn process. In order for the vehicle to start, the BCM (as well as the Passkey module in other vehicles) must identify the resistor pellet in the key, then the BCM sends a password to the PCM. If this password matches the password stored in the PCM, the system enables fuel delivery. So you can see that if either the BCM or PCM are replaced, a relearn procedure is necessary. This same relearn procedure can be used if an ignition key with a different resistance value is used to replace the existing key. Before beginning the relearn, make sure there is a fully charged battery in the vehicle, and both the BCM and PCM are properly powered up and in communication with each other. Now you're ready to initiate the relearn procedure. 1. First, insert the ignition key and turn the ignition switchto the "On" position (Do not start the engine). Leave the switch on for 11 minutes. The security light may flash or be on steady during this 11 minute period. Make sure the light is no longer on or flashing before proceeding to #2 . 2. Turn the ignition switchoff for 30 seconds. 3. Turn the ignition switchto the "On" position (as in step #1) for 11 minutes again. 4. Turn the ignition switchoff for another 30 seconds. 5. Turn the ignition switchto the "On" position for 11 minutes a third time. 6. Turn the ignition switchoff for 30 seconds one final time. 7. Turn the ignition switchto the "On" position one final time and wait 30 seconds. 8. Attempt to start the engine. If the engine starts and runs normally, the relearn is complete. If the engine does not start, check for trouble codes and address them before attempting the relearn procedure again. You can pick one oif these up for $20 or less at a junkyard. For those vehicles that use a BCM, the BCM can learn the resistance value of the existing key by using the relearn process. In order for the vehicle to start, the BCM (as well as the Passkey module in other vehicles) must identify the resistor pellet in the key, then the BCM sends a password to the PCM. If this password matches the password stored in the PCM, the system enables fuel delivery. So you can see that if either the BCM or PCM are replaced, a relearn procedure is necessary. This same relearn procedure can be used if an ignition key with a different resistance value is used to replace the existing key. Before beginning the relearn, make sure there is a fully charged battery in the vehicle, and both the BCM and PCM are properly powered up and in communication with each other. Now you're ready to initiate the relearn procedure. 1. First, insert the ignition key and turn the ignition switchto the "On" position (Do not start the engine). Leave the switch on for 11 minutes. The security light may flash or be on steady during this 11 minute period. Make sure the light is no longer on or flashing before proceeding to #2 . 2. Turn the ignition switchoff for 30 seconds. 3. Turn the ignition switchto the "On" position (as in step #1) for 11 minutes again. 4. Turn the ignition switchoff for another 30 seconds. 5. Turn the ignition switchto the "On" position for 11 minutes a third time. 6. Turn the ignition switchoff for 30 seconds one final time. 7. Turn the ignition switchto the "On" position one final time and wait 30 seconds. 8. Attempt to start the engine. If the engine starts and runs normally, the relearn is complete. If the engine does not start, check for trouble codes and address them before attempting the relearn procedure again.

check fuse

What is the question then ? You have what you feel is a problem, & enough info to explain to a dealer or local repair shop If someone was to guess & that is all anyone without the vehicle to test, can do,then you still have to have the problem diagnosed to find the cause

what did you try? all gears?

Common problem after the battery is unhooked or replaced. You'll get the same results if you turn the AC on also...Unhook the battery, clean your throttle body, with throttle body cleaner (Seafoam works good) with only a rag or plastic bristled brush, no metal as it will scratch it. I prefer to remove the throttle body (4 bolts) to clean both sides, you CAN reuse the hard plastic gasket. When finished, hook the battery back up and drive around for 15 min or so (with no defrost or AC on,everything off), for the computer to relearn the newly cleaned TB. Your problem will be solved for about $8 if you do it yourself.

posible starter drive

bad coolant temp, switch

it could be a problem with the brake switch ajustment. pcm know witch gear is on ,,,alloy the cruise control to works you need with a scanner look at data to see cruise on/off system hope it helps