1999 Chev Tahoe - No Start Security

[Holly]

INTERMITIT NO START LIKE SECURTY COMING ON LOCK DOORS WITH REMOTE THEN LET SET SOMETIMES WILL START NOW NO SERVICE ENG LIGHT WHEN SWITCH IS ON OR NO VOLTAGE GAUGE READING NO SECURITY LIGHT ALSO LAST TIME CUSTOMER HAD TO WAIT FOR ABOUT AN HOUR AND AND FINDLEY STARTED WE CHANGED ING SWITCH BUT STILL SAME PROBLEM CODE P1626C IS IN MEMEORY

[wbuxton]

Does it have an automatic transmission? If so does it have the blue lighted indicator for the PRNDL?

[lauterbachs]

the chevys have problems with the pcm plug getting corrioded.its outside and sometimes gets moisture in it and causes a bad connection...plus on one model there is a service bullitin about antifreeze running down the wire harness and into the pigtail and right into plug for the pcm..iv seen this alot..the service light will not light up and a no start will happen..i usaly get someone to try to start the truck while i do a wiggle test on the pcm harness and usaly itll fire right up...hope that helps........

[lauterbachs]

im tring to find the tsb that has the info on if i find it ill post it

[steven kiser]

i took a quick look in my other repair info system and i would check for a blown fuse for the guages. it seems that this will cause the issue you're having. it gave a detailed flow of diagnostics. btw i've seen these trucks go into a default mode after trying unsucesfully trying to start it over 15 times and system has to be reburned. i've had the pleasure of dealing with these little gems. it can be a major hassel. oh ya, if a remote starter was installed see how the installer overcame the pass key reader. some take reader off of switch and tape a key to it, while others install a transistor inline. i've had issues with these in the past. good luck.................................

[Holly]

Found Key/tumbler assy bad. Replaced, now will start and run but security light comes on and stays on intermittently. Drove for 1 week, opened rear doors at back of vehicle and set off security. Won't run, towed back. Went through the 3-10 minute reprogramming of key and reset. Worked for another 3 days, and security came back on again. Does anyone have an idea of how to eliminate the security on this vehicle????

[lmcca]

you CANNOT remove the security on these vehicles. It is integrated and cannot be undone. Try this:

Causes for P1626 code setting:
Passlock Cylinder
Passlock Housing
Passlock Sensor Harness
Passlock Sensor Harness Filter

Vehicle Theft Deterrent Code P1626. No start.
Tests/Procedures: 1. Access the Passlock sensor 3 wire connector. This is located in the ignition lock cylinder housing.

2. Leaving the connector plugged in, check for 12 volts on the White wire, and less than 0.05 volts on the Black wire. This is the power and ground provided by the Electric Variable Orifice (EVO)/Passlock module.

3. Disconnect the 3 wire connector and verify the module is sending out a 5 volt reference on the Yellow wire. If any of these voltages are incorrect, check for a problem with the wiring, or EVO/Passlock module.

4. Plug the connector back in. During cranking, a resistor in the Passlock sensor will lower the voltage on the Yellow wire. Verify the voltage always drops to the same level. If not, replace the lock cylinder housing and lock cylinder.

5. If the problem continues, replace the lock cylinder housing harness (the filter built into the harness sometimes fails).

6. Perform the relearn procedure by first turning the key to the crank position, then leaving the key on for a minimum of 10 minutes, key off for 10 seconds, then repeat two more times.

good luck,
gary

[steven kiser]

Does anyone have an idea of how to eliminate the security on this vehicle????Holly
Member

Posts: 13
Joined: Tue Oct 16, 2007 9:10 pm
Private message

as far as i know it's built into system. i've had issues with these where the pcm has to be reburned. it's a two staged procedure. first reburn the pcm (some feel this isn't necessary, i do) then program the anti theft module. i'm sure there's a way to by pass it but it's probably something that has to be picked up using bing or google. on some applications like this one i'll check alternator for spikes. i've cured intermitant isseus on gm's by installing a resistor (supressor) at the alternator. i picked this up from a gm tech when i was talking to him about an intermitant shift issue with my suburban. as stated above this is a procedure to use after a thorough visual inspection of the harness. i can't even begin to tell you how many times issues like this have been caused by wiring flaws. if a remote starter was installed at one time the place where the wire was interrupted may be almost broken through. if a wire in the harness is more that 1/2 way wrn through it will cause enough of a resistance issue to trigger the alarm. in my area i'm blessed with three huge communication towers. the more yransmitters that are hung on them the more issues i'm having with older security and remote starter sytems. in my goegraphical location i've gotted into the habit of running my fingers along wires looking for corrousion bumps where some bozo has pierced the wire and not sealed it. i look for the good ole scotch locks as well along with the harness being opened up. you ususlly find these by either the wire hanging out of the loom or it being taped closed and you can see the different tape. on rare occasions i've had gm's wih the combonation of weak batteries and worn high amp draw starters pulling the kam out of the pcm by pulling a heavy amp load and flattening the battery for a split second. srry for the ramble but i had a good night sleep.