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Unknown Driver Message

48K views 15 replies 12 participants last post by  Duder1 
#1 ·
2003 TB 120k miles decided overnight the key we have always used won't work, neither will spare key, get Unknown Driver message, car now DOA. What has caused this? How to rectify?
 
#5 ·
It sounds like the pass-key security has disabled your ignition. This normally prevents an unauthorized key from starting ur truck. Things that will cause ur key to not work are water and/or grease on key or in the ignition switch. If those things don't help, try disconnecting the battery for 10 min., might reset something.
 
#6 ·
It sounds like the pass-key security has disabled your ignition. This normally prevents an unauthorized key from starting ur truck. Things that will cause ur key to not work are water and/or grease on key or in the ignition switch.
I agree that it looks like a failure in the theft deterrent system, but Trailvoys contain Passlock security, not PassKey. Passlock consists of a hall-effect sensor and tamper resistor within the ignition cylinder housing, while the PassKey system uses a transponder in the ignition key head.

Passlock isn't affected by contamination of the key, but there are a number of things that can cause it to fail - high or low voltages, problems with the Passlock circuits, module communication failures...
Your best bet is to have the diagnostic trouble codes pulled - there are at least eight associated with Passlock failure.
 
#12 ·
I know this is an old thread but this is what I found with mine.

My 02 Envoy XL was doing the same thing, unknown driver, no start no crank, abs light, park brake light, air bag light, guages work intermittently, no door lock/unlock function, no power windows, security light and radio locked. It was always some combination of these symptoms every time I turned the key on. I checked all fuses and while I was checking the fuses under the back seat i noticed the 15 amp breaker for the rear wiper was very HOT! So, I pulled the breaker and left it out. After that I was able to get a intermittent "Driver 1" message and when I did the truck would start but would still have different guages and lights on or off but never the same symptoms. So I drove the truck home so I could work on it and was going to get an ignition switch but I didn't. What I found after a few hours was two wires in a harness rubbed through and shorted to the body that go to the tailgate. The harness is up under the headliner where they go through a hole in the body and then out the rubber boot going to the tailgate. One wire was power to the rear wiper and the other was a communication wire to the module that is in the tailgate. When that wire shorted to ground it shorted the commmunication bus and made everything stupid. What you have to do is pull the rubber door seal down to get under the headliner and you can see where the harness goes through an unprotected oval hole in the body. These wires move every time you open the tailgate and if they rub you may have a short. I repaired my wires and protected the opening with some vacuum hose that I slit down the side and placed on the sheet metal around the opening. Of course this is what I found with mine and yours may be shorted somewhere else but this is so easy to check that I would look there first. Good luck and hope my experience with this problem helps someone else.
 
#14 ·
Fixed it! Found the issue on mine. The dash lights would cut out randomly and leave nothing but the gauges working. Then it would give me unknown driver and not start, no radio and no dash. Some days we would go to start it and the battery would be dead. Ongoing issue, intermittent. Today it stayed on unknown driver long enough for me to troubleshoot so I:
1. Put key in the ignition and turned it to On
2. Removed the fuse cover under the back seat.
3. Pulled module fuses until suddenly the door ajar started sounding and the radio came on.
4. Looked up the fuse location.

For me it turned out to be the PDM, which stands for the passenger door module. I have had issues with the passenger door electronics before so this didn't come as a great surprise. It seems any module that is connected to the BCM; DDM, PDM, Radio, Ect.. can cause this kind of issue so just remove power from each of the modules until you find the culprit. Best of luck.
 
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