I have a 99 Tahoe w/73,000 miles. On Sept. 05 I had a 180 diagnosis ABD Pass Lock Sensor replaced for the following problem. You'd put the key in the ingnition, crank it over, the Tahoe would Start right up and in 1 or 2 seconds Shut Down and the Security light would be on solid. For 9 months (cooler/dryer weather) I had no problem then on June 06 the problem came back. The Tahoe wouldn't start all day and finally started right up the next morning. Back to the Dealership and no codes in the computer. Dealership sprayed water onto the engine because I always seem to have this problem during damp weather and they suggested a tune up. $480 bucks later I have a tune up. Problem acted up again on Aug 06, again with the Tahoe sitting outside by a Marina where it was very damp that night. From looking online it sounds like it might be a "Pass Lock Module". If there's anyone that can help I'd appreciate it. Seems like I can't leave the city and have it outside in the dampness. Thanks Again, Mike

 

your lucky it took me 2000 dollars before i found out what the problem was and i had my moduke changed out and my 99 tahoe with 165000 mile runs better then ever.

 

TSB 01-08-56-004A (Document ID# 820566) deals with this exact problem on 1999 Tahoe's.

Cause
The condition(s) may be due to an incorrect Passlock™ sensor voltage received by the EVO/Passlock™ module from the Passlock™ sensor due to the following conditions. Most intermittent conditions are caused by faulty electrical connections or wiring.

• A 7 ohm variation in the sensor ground circuit wiring, circuit 1057

• A 100 ohm variation in the Passlock™ sensor signal wiring circuit, circuit 1836

Inspect for the following items:

• Broken wiring inside the insulation.

• A poor connection between the male and female terminal at the connector. Refer to Testing for Proper Terminal Contact under Testing for Intermittent and Poor Connections in Wiring Systems for the specific procedure.

• A poor terminal to wire connection. Some conditions that fall under this description include poor crimps, poor solder joints, crimping over the wire insulation instead of the wire itself, and corrosion in the wire to terminal contact area.

• Wire insulation that is rubbed through. This causes an intermittent short as the bare area touches other wiring or parts of the vehicle.

• A poor connection between the male and female terminal at a connector. This poor connection may be the result of contamination or deformation.

• Contamination may be caused by the connector halves being improperly connected. A missing or damaged connector seal, damage to the connector itself, or exposing the terminals to moisture and dirt can also cause contamination. Contamination, usually in the underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit.

- Separate the connector halves.

- Visually inspect the connector halves for contamination. Contamination may result in a white or green build-up within the connector body or between terminals. This causes high terminal resistance, intermittent contact, or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety including the terminals, the seals, and the connector body.

• Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves, or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal connector tang, can result in poor terminal contact causing an open or intermittently open circuit. Using an equivalent male terminal from the J 38125-B, test that the retention force is significantly different between an good terminal and a suspect terminal. Replace the female terminal in question.