99 Yukon - fuel delivery issue?

[SunlitComet]

PASSLOCK Reprogramming Seed and Key DISCLAIMER
This step by step procedure is intended to augment the PasslockTM Diagnostic Repair Procedures. Sole reliance on this procedure may lead to unintended results.

EQUIPMENT

• CD-ROM database containing the passlock seed and key algorithm loaded on a computer with class 2 capability
• Scan Tool TECH 2 or a compatible scan tool

CONDITIONS

IMPORTANT: If a new Vehicle/Powertrain Control Module (VCM/PCM) is being installed for the first time the manufacturing enable bit will be set and the auto learn procedure may not be necessary.

The following procedure allows the relearning of the EVO/PasslockTM module or the VCM/PCM learned data code after the replacement of any of the following parts:

• The EVO/PasslockTM module
• The passlockTM sensor
• The VCM/PCM

The EVO/PasslockTM module will set the DTC B3031 module in the learn mode when entering the reprogramming procedure.

STEPS

IMPORTANT: Erase the passlockTM related Diagnostic Trouble Codes (DTCs) that are stored in the VCM/PCM. If there are any powertrain related DTCs, record those DTCs then refer to A Powertrain On Board Diagnostic (OBD) System Check. See: Powertrain Management\Computers and Control Systems
IMPORTANT: In addition to the time involved in performing the specific steps, the Seed and Key procedure accomplishes the same task in 10 minutes as the Auto Lean procedure does in 30 minutes . Use either one of these two procedures.

The following is the Seed and Key Learn Procedure:

1. Insure the ignition key is in the ON position.
2. Clear all EVO/passlockTM module and VCM/PCM DTCs, record those DTCs then refer to A Powertrain On Board Diagnostic (OBD) System Check. See: Powertrain Management\Computers and Control Systems
3. With scan tool (TECH 2) connected to the vehicle, select "Programming/Request Info" from menu, then follow instructions.
4. Disconnect scan tool from vehicle and perform "Service Programming System/VTD Learn" with Techline terminal, then follow instructions.
5. Reconnect scan tool to the vehicle.
6. Follow instructions on the scan tool to perform the VTD password learn on the vehicle, this takes about 10 minutes.
7. After 10 minutes , the SECURITY indicator will turn OFF. The new security code is ready to be communicated among the Passlock sensor, EVO/Passlock module and VCM/PCM. The new Password is learned on the next ignition lock cylinder cycle from OFF-to-CRANK-to-ON (start attempt).

 

[992dr]

I thought the lights were mostly normal - ABS, Seatbelt, Airbag, etc. I know I've seen the solid orange "security" light a few times while starting it. I'll give it a jump and try it again, taking particular note of the lights this time.

But I'm a little stumped about the nature of the thread you posted (I read the whole thing). The thread starter mentioned something about a "passlock" system causing his car not to start. But that applies to cars that use a key with an embedded resistor, i.e. the ones that have the little black bumps on the surface of the key itself, right? So if I'm understanding that correctly, I'm not sure how a new ignition was solvent in fixing his problem, or why he had to do a "relearn" procedure if the key and the keyless entry are both passive devices.

But one other thing I should note, the windshield wipers work very intermittently in my truck (but it seems like once they start working, they work for as long as I need them). I believe they're tied into the ignition, so I guess it's possible the ignition could be the root cause of the failure to stay running and the intermittent wipers as well.. but one would think if the ignition were to blame, there wouldn't be any fire at all, which isn't the case. I'm still trying to figure out how an ignition would solve the guy's problem in that thread, and we don't know that it did either, because he never posted again after the one involving the "relearn" procedure.

That link I posted was me
The security lite narrows down the problem, if its on, that is most likely the culprit.
As said the components are in the column not the key.
I forgot to post about the relearn. The replacement of the said parts resolved my problem and after I did the relearn everything has been 100%.
This is what I did for the Relearn Procedure
1.Turn ON the ignition, with the engine OFF.
2.Attempt to start the engine, then release the key to ON (vehicle will not start).
3.Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
4.Turn OFF the ignition, and wait 5 seconds.
5.Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes

As for your wipers, the same thing happened with me. I replaced both the board and motor. No more problems.

 

[letsbangout]

That link I posted was me
The security lite narrows down the problem, if its on, that is most likely the culprit.
As said the components are in the column not the key.
I forgot to post about the relearn. The replacement of the said parts resolved my problem and after I did the relearn everything has been 100%.
This is what I did for the Relearn Procedure
1.Turn ON the ignition, with the engine OFF.
2.Attempt to start the engine, then release the key to ON (vehicle will not start).
3.Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
4.Turn OFF the ignition, and wait 5 seconds.
5.Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes

Thanks!

So to summarize what I've learned here:
1) The symptom of a passlock security failure is a failure to start, followed by a blinking or solid SECURITY light
2) The resolution is to either replace the two parts you named in the other thread, and complete the re-learn procedure you mentioned above (I'm elated such a thing exists, because the one SunlitComet posted would surely have to be performed by a dealer) - or - feed ignition voltage to engage a (presumably externally-mounted) fuel pump relay.

Indeed, when I took another look at my truck and charged up the battery good, I turned the key to ON and waited a few seconds for the security light to disappear, then it started right up the first time. I've done about 5 or 6 drive cycles on it and no MIL light or problems starting it up (though I should codescan it soon). Now I'll know what to look for, should it ever happen in the future.

As for your wipers, the same thing happened with me. I replaced both the board and motor. No more problems.

Somewhere in the back of my mind, I still think it's tied to the ignition somehow (once I was able to cycle the ignition off/on and make the wipers start working, albeit, that's just anectotal evidence). But I did manage to locate (what I think is) the board you're referring to, on a diagram that shows it somewhere around or behind the glove compartment? I'll try testing and/or replacing that at the first sign of trouble, as both of my interior fuses that say "wiper" had 13 volts on them when I probed them while the problem was occurring.

Thanks again for the help all. I'll monitor my problem over the next several days and report back.

 

[992dr]

The security lite will turn on when the ignition is engaged, if it stays on this is more than likely your problem.

One thing you should note. This will NOT happen consistantly, it may happen onces a day or three times a day, heck it may not happen for a week. That's what is so aggrivating about this. As you can see in my thread, it got worse as time went on. What also sucked was, it went from starting in roughly ten minutes to taking almost two hours to start.
Basically, it gets worse over time.


The wiper board is on the firewall in front of the driver as is the motor. Simple easy fix and relatively inexpensive.

 

[SunlitComet]

wiper board is in the motor assembly under hood.

 

[letsbangout]

Thanks all for the additional replies. I've done another 7 or 8 drive cycles without issue. When I remember to do it, I now turn the key into ON and let it sit for about 5 seconds until the "security" light goes off, though it's not yet given me a problem cranking up since I've known about the nature of the problem. Funny how that works!

Regarding the wiper, that gives me more troubleshooting ammo. I think I'll probably change out the O2 sensors first though; it's a persistent code with the heaters in one of the sensors, and it seems to be contributing to a hard shift from 1st to 2nd gear. That problem, incidentally, seems to have gotten better after replacing the MAP sensor, which is responsible (as I understand it) for helping the VCM determine the engine's load. It stands to reason that a computer that thinks the engine is loaded down (i.e. while towing) would make the tranny shift harder to compensate. But that's purely anecdotal until I bite the bullet.