2002 Tahoe wont run

[Steve Berg]

What specific DTC is being set? If more than one, please post all.

I managed to get a code reading. P1626

 

[rockola1971]

1. Without key security on at all time. When turning key it cranks ant try to start.
2. It starts and dies after a second or two.
3. Lights and powerlook worked as normal before and latest halv a hour before i
parked thre car .
4. 12.67V. I also use a 5 amp maintenance charger when working with the car.
12,67V it whitout charger and battery resting.

People had light and powerlock problems with the passlock failing and in adition i have the light on to tell me the passlock plays up. Have a PK3+ on my keys so i guess that is a Passkey 3+ system in my car.

You are welcome to Norway but its to cold to chase women, better to repair old US cars

OK now things are startring to make some sense.

Engine starts then dies a few seconds later AND you have P1626 which is the fuel pump disable because your PASSLOCK system is engaged. To verify the Passlock is engaged you can goto your scanner and check the state it is in. There are 3 main components to the PASSLOCK system. The passlock ssensor, BCM and the magnet in your ignition lock cylinder. The magnet doesnt go bad. The PASSLOCK sensor is the typical failure point but there is a remote chance that your BCM is the culprit. The fact that your power locks and interior lights are acting up leads me to believe your BCM (Body Control Module) is at fault, however it is possible that your PASSLOCK sensor and Ignition switch (not to be confused with ignition lock cylinder) are causing the problems. The Ignition switch is cheap and easy to replace. The PASSLOCK sensor I believe only comes preinstalled in an igniton lock cylinder housing and in order to replace that you will have to pull the steering wheel.
If you have verified all the main grounds are clean and tight, especially the one behind the engine block to firewall as well as the one below drivers door on chassis near firewall then I would replace BCM and it has to be programmed to your VIN. Bad grounds can cause the BCM to act up because it has lost its ground reference that it uses to make decisions and institute them as a voltage output. If parts are hard to get for Tahoes there in Norway, there is ebay and we have 1000's of salvage yards here in the U.S. and we can work something out to get your part to you. You will need the GM part# off of your BCM to get the correct BCM. There could be multiple part numbers for your model year.

Honestly if I am in the steering column to replace the Igntion Cylinder housing then while I have it all opened up I would replace the Ignition switch since they are cheap enough and easy to replace. Considering the vehicle age I would do it now or you will be doing it later.

Remember when the system is taken apart this far and parts replaced a PASSLOCK relearn is REQUIRED.


Here is a video that explains alot and shows the work needed to get the parts replaced. It is not difficult. Just tedious.

 

[Steve Berg]

OK now things are startring to make some sense.

Engine starts then dies a few seconds later AND you have P1626 which is the fuel pump disable because your PASSLOCK system is engaged. To verify the Passlock is engaged you can goto your scanner and check the state it is in. There are 3 main components to the PASSLOCK system. The passlock ssensor, BCM and the magnet in your ignition lock cylinder. The magnet doesnt go bad. The PASSLOCK sensor is the typical failure point but there is a remote chance that your BCM is the culprit. The fact that your power locks and interior lights are acting up leads me to believe your BCM (Body Control Module) is at fault, however it is possible that your PASSLOCK sensor and Ignition switch (not to be confused with ignition lock cylinder) are causing the problems. The Ignition switch is cheap and easy to replace. The PASSLOCK sensor I believe only comes preinstalled in an igniton lock cylinder housing and in order to replace that you will have to pull the steering wheel.
If you have verified all the main grounds are clean and tight, especially the one behind the engine block to firewall as well as the one below drivers door on chassis near firewall then I would replace BCM and it has to be programmed to your VIN. Bad grounds can cause the BCM to act up because it has lost its ground reference that it uses to make decisions and institute them as a voltage output. If parts are hard to get for Tahoes there in Norway, there is ebay and we have 1000's of salvage yards here in the U.S. and we can work something out to get your part to you. You will need the GM part# off of your BCM to get the correct BCM. There could be multiple part numbers for your model year.

Honestly if I am in the steering column to replace the Igntion Cylinder housing then while I have it all opened up I would replace the Ignition switch since they are cheap enough and easy to replace. Considering the vehicle age I would do it now or you will be doing it later.

Remember when the system is taken apart this far and parts replaced a PASSLOCK relearn is REQUIRED.


Here is a video that explains alot and shows the work needed to get the parts replaced. It is not difficult. Just tedious.

Thanks. I have a passkey 3+ system. I ordered a vin programed remanufactured BCM from US and a new key housing with sensor inside. Very litle to find regarding passkey 3+ system and how to replace parts but i hav the bcm out and removed the shroud around the steeringwheel to get to the exciter which i also have ordered new from France. Hopefully the harness is ok as it seams very difficult to find the correct one new. Anyway thanks for your parts offer, very kind but i have good contacts your place as i have been driving US cars for ages.

 

[Steve Berg]

Thanks. I have a passkey 3+ system. I ordered a vin programed remanufactured BCM from US and a new key housing with sensor inside. Very litle to find regarding passkey 3+ system and how to replace parts but i hav the bcm out and removed the shroud around the steeringwheel to get to the exciter which i also have ordered new from France. Hopefully the harness is ok as it seams very difficult to find the correct one new. Anyway thanks for your parts offer, very kind but i have good contacts your place as i have been driving US cars for ages.

My Switch looks like this in the lock end and i have 5 wires going to the steering angel system.

 

[Steve Berg]

Thanks. I have a passkey 3+ system. I ordered a vin programed remanufactured BCM from US and a new key housing with sensor inside. Very litle to find regarding passkey 3+ system and how to replace parts but i hav the bcm out and removed the shroud around the steeringwheel to get to the exciter which i also have ordered new from France. Hopefully the harness is ok as it seams very difficult to find the correct one new. Anyway thanks for your parts offer, very kind but i have good contacts your place as i have been driving US cars for ages.

Rock auto have a ACDELCO D1466E which suppose to be for my car but it dont look like mine. A win search on gm parts online say gm # 89058142 but this is discontinued and no pictures to compare with so i dont know. Might leave the old switch and hope for the best. That thing on the switch going in to the lock housing, is that a part which normally fail?

Steve

 

[rockola1971]

Rock auto have a ACDELCO D1466E which suppose to be for my car but it dont look like mine. A win search on gm parts online say gm # 89058142 but this is discontinued and no pictures to compare with so i dont know. Might leave the old switch and hope for the best. That thing on the switch going in to the lock housing, is that a part which normally fail?

Steve

Usually the ingition switch failure points are the internal contacts. They either get burned causing an electrical open circuit or they weld themselves together and are then always closed contacts and that could be very bad depending on which set weld.

 

[Steve Berg]

Usually the ingition switch failure points are the internal contacts. They either get burned causing an electrical open circuit or they weld themselves together and are then always closed contacts and that could be very bad depending on which set weld.

With ignition switch do you mean that part soldered to the harness that push in to the bottom ov the key housing and have two plugs at the end which one is the beeper if you leave the key in the lock? If, i guess that means the whole harness and thats my problem. They are discontinued.

Steve

 

[rockola1971]

With ignition switch do you mean that part soldered to the harness that push in to the bottom ov the key housing and have two plugs at the end which one is the beeper if you leave the key in the lock? If, i guess that means the whole harness and thats my problem. They are discontinued.

Steve

Goto video above to the 7:30 mark and it shows the removal of the ignition switch. The ignition switch is not discontinued. If a wire in the steering column is broken it can be easily repaired.

 

[Steve Berg]

Goto video above to the 7:30 mark and it shows the removal of the ignition switch. The ignition switch is not discontinued. If a wire in the steering column is broken it can be easily repaired.

Thats the problem i have. A passkey III have a transmitter around the key and it was discontinued in 2015 by GM and no 3rd party switches around. Have 5. leads from the switch to the transmitter and all available switches have 3. The transmitter i have is from Delphi and also discontinued (see Picture) so i ordered a complete rebuild kitt to Passlock II as they are everyvere for sale.

Steve

 

[rockola1971]

Thats the problem i have. A passkey III have a transmitter around the key and it was discontinued in 2015 by GM and no 3rd party switches around. Have 5. leads from the switch to the transmitter and all available switches have 3. The transmitter i have is from Delphi and also discontinued (see Picture) so i ordered a complete rebuild kitt to Passlock II as they are everyvere for sale.

Steve

You have the PASSLOCK 3 system on a 2002 tahoe? And you have a transmitter on your ignition key? Pic of ignition key? I have (2) 2003 Tahoe LT's and neither have that crap on them. Maybe its a made for european market type situation.

 

[Steve Berg]

You have the PASSLOCK 3 system on a 2002 tahoe? And you have a transmitter on your ignition key? Pic of ignition key? I have (2) 2003 Tahoe LT's and neither have that crap on them. Maybe its a made for european market type situation.

Might be a export thing. The transmitter is under the rubber bit onthe key so you dont se it. Anyway, had all my parts now so i rebuild the whole ting to passkey II. New refurbished computer, new complete switch with harness, lock and keys. Should do the trick i hope.

 

[Steve Berg]

Anyone who knows what kind of signal the ECM receives from the BCM. As far as i can see there is two wires from the bcm to the ecm. I am twisting my head with this. Have replaced the whole harness with new ignition housing, lock and keys + installed a refurbished bcm programmed to VIN. Stil have the same problem, just starts and then cut. Security light and charge light alternate when ignition is on and security light permanent with ignition to off. Due to this i do not think the problem is with the ecm but please correct me if i am wrong.

 

[engrgrl]

Anyone who knows what kind of signal the ECM receives from the BCM. As far as i can see there is two wires from the bcm to the ecm. I am twisting my head with this. Have replaced the whole harness with new ignition housing, lock and keys + installed a refurbished bcm programmed to VIN. Stil have the same problem, just starts and then cut. Security light and charge light alternate when ignition is on and security light permanent with ignition to off. Due to this i do not think the problem is with the ecm but please correct me if i am wrong.

a few questions:
A. did you end up with a passkey II (where there is a visible resistor on the key)? Did you try the passkey II relearn procedure? [1. Insert ignition key and turn to the “ON ” position. Do not attempt to start the engine. Leave the key in the “ON ” position for approximately 11 minutes. The security light will be steady on or flashing for the 11-minute period. Do not proceed to Step 2 until the security light turns off or stops flashing. 2. Turn the ignition switch to the “OFF ” position for 30 seconds. 3. Turn the ignition switch to the “ON ” position as in Step 1 for 11 minutes. 4. Turn the ignition switch to the “OFF ” position for 30 seconds. 5. Turn the ignition switch to the “ON ” position as in Step 1 for 11 minutes for a third time. 6. Turn the ignition switch to the “OFF ” position for 30 seconds for a third time. 7. Turn the ignition switch to the “ON ” position for 30 seconds. 8. Turn the ignition switch to the “OFF ” position. 9. Attempt to start the engine]

B. did you end up with a passkey III (where there would be a transponder inside the key plastic part)? Did you try the passkey III relearn procedure ? Other folks will need to comment here, but if the truck originally had the Passkey 3+ system, then I think the PCM needs to learn the new "fuel continue password" when the BCM is replaced by doing the relearn test. [When performing this relearn all previously learned keys will be erased. Additional keys may be relearned immediately after the first key has been learned by inserting the additional key and turning the ignition switch to on within 10 seconds of removing the previously learned key. 1. Insert a master key (black head) into the ignition switch. 2. Turn key to the “ON ” position without starting the engine. The security light should turn on and stay on. 3. Wait for 10 minutes or until the security light turns off. 4. Turn key to the “OFF ” position for 5 seconds. 5. Turn key to the “ON ” position without starting the engine. Security light should turn on and stay on. 6. Wait for 10 minutes or until the security light turns off. 7. Turn key to the “OFF ” position for 5 seconds. 8. Turn key to the “ON ” position without starting the engine The security light should turn on and stay on. 9. Wait for 10 minutes or until the security light turns off. 10. Turn key to the “OFF ” position. The key transponder information will be learned on the next start cycle. 11. Start the vehicle. If the vehicle starts and runs normally, the relearn is complete. 12. If additional keys need to be relearned, turn the key to the “OFF ” position. 13. Insert the next key to be learned. Turn the key to the “ON ” position within 10 seconds of removing the previously used key. 14. Wait for security light to turn off. It should happen fairly quickly. You may not notice the lamp as the transponder value will be learned immediately. 15. Repeat steps 12 through 14 for any additional keys. NOTE: If the theft deterrent relearn procedure does not work, please try the procedure again]

C. Have you replaced the ground and/or positive battery cables recently? Other GM cars and trucks sometimes have corrosion inside the battery cables (not visible from outside) that causes voltage issues that can be a fail to start and presumably a BCM not responding properly. Other folks would need to comment on this idea, but I'm thinking that's what's preventing my Tahoe from starting part of the time (I have two types of intermittent fail to start: sometimes no interior lights/no dash lights/etc OR sometimes have interior lights/dashlights but decides to not crank at all -- I'm suspicious of the battery cables on the no interior lights/no dash lights occurrences.)


To answer your question, I believe the BCM sends a serial data signal to the PCM ( the "fuel continue password" ) that is a coded signal -- supposedly the relearn procedure above would let the PCM learn to accept the "new" "fuel continue password".


From what I have seen the Tahoes sold in USA that are model year 2002 have an ignition switch that is integrated to a wiring harness and sells for about $65 USD. The Tahoes sold in the USA that are model year 2003 have an ignition switch that unplugs out of the wiring harness and replaces separately (with no harness available) sells for about $15 USD.

 

[engrgrl]

Secondary question for the experts out there: If there's an issue with the vehicle ground (like the corroded ground cable) could that cause the BCM to fail to pass the correct serial data message to the PCM?

asking because of this:
Ignition Switch
The ignition switch contains the wiring and electrical switching portion of the column mounted ignition assembly. The ignition switch includes wiring pigtails which connect it to the base of the column connector. The Passlock™ sensor is an internal resistor within the ignition switch.

The ignition switch receives a 5-volt reference from the body control module (BCM) via the ignition key resistor signal circuit. When in the start position, the 5-volt reference travels through the Passlock™ sensor within the ignition switch. This creates a unique voltage value which is returned to the BCM via the off/run/crank voltage circuit.

Body Control Module (BCM)
The body control module (BCM) contains the logic of the theft deterrent system. The BCM provides the 5-volt reference to operate the Passlock™ sensor. The BCM also measures the voltage of the off/run/crank voltage. The voltage measured will indicate whether the Passlock™ sensor has been activated and whether the resistance value from the sensor is a valid value or the tamper value. If voltage measured is in the valid range, the BCM compares this voltage to a previously learned voltage code. If the voltage codes match, the BCM sends a serial data message containing a password to the engine control module (ECM). If the voltage codes do not match, or the voltage is in the tamper range, or there is a circuit fault, the BCM will not send the correct password to the ECM, and the vehicle will not start.

Engine Control Module
The engine control module (ECM) contains the remainder of the logic of the theft deterrent system. If a serial data message containing a valid password is received from the body control module (BCM), the ECM will continue to allow the fuel injectors to operate. The ECM will allow the fuel injectors to operate until it decides there is no valid password coming from the BCM. If the ECM does not receive a serial data message, or receives a serial data message with an incorrect password, the engine will crank and will not run or will start and stall immediately.

 

[Steve Berg]

a few questions:
A. did you end up with a passkey II (where there is a visible resistor on the key)? Did you try the passkey II relearn procedure? [1. Insert ignition key and turn to the “ON ” position. Do not attempt to start the engine. Leave the key in the “ON ” position for approximately 11 minutes. The security light will be steady on or flashing for the 11-minute period. Do not proceed to Step 2 until the security light turns off or stops flashing. 2. Turn the ignition switch to the “OFF ” position for 30 seconds. 3. Turn the ignition switch to the “ON ” position as in Step 1 for 11 minutes. 4. Turn the ignition switch to the “OFF ” position for 30 seconds. 5. Turn the ignition switch to the “ON ” position as in Step 1 for 11 minutes for a third time. 6. Turn the ignition switch to the “OFF ” position for 30 seconds for a third time. 7. Turn the ignition switch to the “ON ” position for 30 seconds. 8. Turn the ignition switch to the “OFF ” position. 9. Attempt to start the engine]

B. did you end up with a passkey III (where there would be a transponder inside the key plastic part)? Did you try the passkey III relearn procedure ? Other folks will need to comment here, but if the truck originally had the Passkey 3+ system, then I think the PCM needs to learn the new "fuel continue password" when the BCM is replaced by doing the relearn test. [When performing this relearn all previously learned keys will be erased. Additional keys may be relearned immediately after the first key has been learned by inserting the additional key and turning the ignition switch to on within 10 seconds of removing the previously learned key. 1. Insert a master key (black head) into the ignition switch. 2. Turn key to the “ON ” position without starting the engine. The security light should turn on and stay on. 3. Wait for 10 minutes or until the security light turns off. 4. Turn key to the “OFF ” position for 5 seconds. 5. Turn key to the “ON ” position without starting the engine. Security light should turn on and stay on. 6. Wait for 10 minutes or until the security light turns off. 7. Turn key to the “OFF ” position for 5 seconds. 8. Turn key to the “ON ” position without starting the engine The security light should turn on and stay on. 9. Wait for 10 minutes or until the security light turns off. 10. Turn key to the “OFF ” position. The key transponder information will be learned on the next start cycle. 11. Start the vehicle. If the vehicle starts and runs normally, the relearn is complete. 12. If additional keys need to be relearned, turn the key to the “OFF ” position. 13. Insert the next key to be learned. Turn the key to the “ON ” position within 10 seconds of removing the previously used key. 14. Wait for security light to turn off. It should happen fairly quickly. You may not notice the lamp as the transponder value will be learned immediately. 15. Repeat steps 12 through 14 for any additional keys. NOTE: If the theft deterrent relearn procedure does not work, please try the procedure again]

C. Have you replaced the ground and/or positive battery cables recently? Other GM cars and trucks sometimes have corrosion inside the battery cables (not visible from outside) that causes voltage issues that can be a fail to start and presumably a BCM not responding properly. Other folks would need to comment on this idea, but I'm thinking that's what's preventing my Tahoe from starting part of the time (I have two types of intermittent fail to start: sometimes no interior lights/no dash lights/etc OR sometimes have interior lights/dashlights but decides to not crank at all -- I'm suspicious of the battery cables on the no interior lights/no dash lights occurrences.)


To answer your question, I believe the BCM sends a serial data signal to the PCM ( the "fuel continue password" ) that is a coded signal -- supposedly the relearn procedure above would let the PCM learn to accept the "new" "fuel continue password".


From what I have seen the Tahoes sold in USA that are model year 2002 have an ignition switch that is integrated to a wiring harness and sells for about $65 USD. The Tahoes sold in the USA that are model year 2003 have an ignition switch that unplugs out of the wiring harness and replaces separately (with no harness available) sells for about $15 USD.

i ended up buying the passlock II complete set with new keys, switch and housing. The passlock and passkey do the same job i believe. Problem is that export cars is fitted with a different system so i also bought a bcm and a win coded pcm from USA and with securiy disable on the pcm. Should arrive on monday and i should know for sure if this makes the car start. Have a krank and ignition with the new key and only code is the start signal to the pcm. I tryed all different ways to relearn but my security light wont go off, tried ignition on for hours even but security light did not change.

 

[Steve Berg]

Ok. Have the car running with a security delete on the PCM. Export Tahoes have a very different security set up from those sold in USA. My only issue now is that the security light is on all the time in the multi display. Anyone who knows if it is possible to program (delete) the signal which trigger this warning and still have all the other warnings coming up in the display? Must be a wire somwhere that feed the security signal to the instrument panel.

 

[rockola1971]

Ok. Have the car running with a security delete on the PCM. Export Tahoes have a very different security set up from those sold in USA. My only issue now is that the security light is on all the time in the multi display. Anyone who knows if it is possible to program (delete) the signal which trigger this warning and still have all the other warnings coming up in the display? Must be a wire somwhere that feed the security signal to the instrument panel.

Believe that comes across the serial data line. Just cut the bulb off the board or throw black tape over the symbol on the IC.

 

[Steve Berg]

Believe that comes across the serial data line. Just cut the bulb off the board or throw black tape over the symbol on the IC.

It is a multi display with all different alarms in the same display.

 

[rockola1971]

It is a multi display with all different alarms in the same display.

All of that can be deleted in the eprom of the IC. Just like turning on/off the tranny temp gauge feature.

 

[Frankttaylor]

Anyone who knows what kind of signal the ECM receives from the BCM. As far as i can see there is two wires from the bcm to the ecm. I am twisting my head with this. Have replaced the whole harness with new ignition housing, lock and keys + installed a refurbished bcm programmed to VIN. Stil have the same problem, just starts and then cut. Security light and charge light alternate when ignition is on and security light permanent with ignition to off. Due to this i do not think the problem is with the ecm but please correct me if i am wrong.

Did you ever figure this out? I am having the same problem.