# 2008 Chevy Colorado Passlock issue



## raylo32 (Nov 25, 2006)

Visiting my mom, her 2008 Chevy Colorado 4x4, I5, auto is having intermittent no crank, no start issues with the "security" light flashing. I believe this indicates a problem with the truck's Passlock system. This is the version that apparently has the security mechanism inside the ignition switch, not the little resistor in the key like the older PASSKEY/VATS systems.

I have bypassed the older VATS before by splicing in a resistor equivalent to the one on the key but that method does not appear to be viable for this PASSLOCK system. I did find some information about people claiming to bypass one version of PASSLOCK by measuring the resistance in the cylinder but those threads referred to wire bundles and colors (3-wire bundle from sensor with red/wh, black, and yellow, like I saw with the older VATS) that are not available in our truck, so I don't think the technique applies.

So I am thinking that the only alternative is to replace the ignition switch and do a security relearn. Unfortunately I don't have the time or tools here to do that so it will need to go to a shop or the dealer.

Anyone here have experience with this particular flavor of PASSLOCK?


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## Brainbucket (Mar 30, 2015)

The immobilizer system determines whether engine starting will be allowed based on a pull-down voltage created by the security resistor located in the ignition switch. When the ignition is in the START position, 5 volts is applied to the security resistor by the body control module (BCM) via the ignition key resistor signal circuit. A ground path is provided back to the BCM by the off/run/crank voltage circuit. This circuit is also used in power moding operations. With the ignition in the START position, a voltage value is produced on ignition key resistor signal circuit based on the resistance of the security resistor. Each available resistor will produce a unique voltage value seen at the BCM. During immobilizer programming, the BCM learns this voltage value. On a start attempt, the BCM will compare actual voltage seen to the learned value. If the voltage seen and the learned value do not match, vehicle starting will be disabled.

The components of the immobilizer system are as follows:

* Ignition switch
* Body Control Module (BCM)
* Engine Control Module (ECM)
* Security indicator 









Looks like you can do the same thing on this system.:vs_cool:


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## raylo32 (Nov 25, 2006)

Excellent, thanks BB. Do you happen to have a higher resolution image? I can't read the wire colors. It looks like maybe I'd have to install the resistor between white/yellow and white/blue (can't really tell from image), then cut the white/blue on the ignition switch side of the new resistor.

I have already removed the ignition switch and procured a new one from local Chevy so will go ahead with that, and keep the resistor trick on standby.


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## Brainbucket (Mar 30, 2015)

On right side of page, at bottom (ignition switch side) going up is a WH/BU wire and at the connector turn WH. Left side down going up from ignition switch is a WH/YE and at connector turns WH/BK.:vs_cool:


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## raylo32 (Nov 25, 2006)

Hey BB I could use a little help. Putting everything back is straightforward except the auto trans shift lock doesn't want to cooperate. The cable does not pull up when I move the shifter so the key will operate full range and come out no matter if the trans is in parr or gear. I mean the cable doesn't move at all when I move the shifter, like maybe it is disconnected in the shift arm. But I didn't touch that, alls I did was pop off the connector on the old ignition switch. What's happening?? I am running out of time here.


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## raylo32 (Nov 25, 2006)

Never mind I figured it out. It works the other way, the key pulls on the shifter and the lock is controlled by a solenoid. I remembered that you need to press the brake to shift out of park.


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## raylo32 (Nov 25, 2006)

Well, success, sort of. I finished the install and did the re-learn and truck is starting fine. But there is still something not quite right with the tranny shifter lock. With the key off I can move the shifter from park to any gear, IOW th elock is disengaged. But with the engine running the shifter is properly locked in park until I press the brake, then once depressed allows shifting.

I am guessing this has to do with the position of the lock cylinder when I inserted the cable connector. I think I inserted it with the key off, so maybe I need to go back in there, pull the connector, then put the key in run and reinsert the connector. Have to be careful in the interim.


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## raylo32 (Nov 25, 2006)

I am thinking the dealer sold me the wrong part. I got part 1579-5322 which a google search says does fit Colorado but I also found another AC Delco part match - part number D1462G GM Original Equipment Ignition Lock Housing, that looks identical and lists the same attributes but adds one more: "shaft lock".

Bottom line the new switch works fine but it's like a car from the 1960s before there were steering column and trans locks. I can turn the steering wheel and shift the trans without even having the key in the ignition. There is no mechanical steering column and trans lock. Now the trans does lock in park with the motor running until I press the brake. That is the function of the little cable from the switch so that is working fine. I just don't have the hard mechanical lock when shut down.

This is strange, tho. I wouldn't think it would be legal to have a vehicle w/o a steering column and trans lock. Haven't seen that for decades. So why would GM even sell a switch housing that didn't provide that?


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## raylo32 (Nov 25, 2006)

Here is the Rock Auto listing. D1403G and D1426G look identical and both apply for I5, 4L60, only difference is "shaft lock". Our truck doesn't have the BAE security system (that I understand that is Canada only) so other listed part cleary doesn't apply. The one I got from the dealer is the equivalent to D1430G. It is AC Delco P/N 15795322.

2008 CHEVROLET COLORADO 3.7L L5 Ignition Lock Housing | RockAuto


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## raylo32 (Nov 25, 2006)

Short video demonstrating the issue:


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## Brainbucket (Mar 30, 2015)

*Ignition Lock Cylinder Replacement*

*Removal Procedure*

1. Remove the steering column trim covers. Refer to Steering Column Trim Covers Replacement.
2. Turn the ignition lock cylinder to the accessory position.
3. Insert the 90 degree tip of a pick type tool into the ignition lock cylinder access hole.
4. Push and hold the ignition lock cylinder retaining pin down.
5. Pull the ignition lock cylinder away from the steering column.

*Installation Procedure*

1. Install the ignition lock cylinder by performing the following procedure:

1. Turn the ignition lock cylinder to the accessory position.
2. Push the ignition lock cylinder in until the retaining pin locks it in place.

2. Install the steering column trim covers. Refer to Steering Column Trim Covers Replacement.

This is different than regular trucks as you have to have it in the start position to remove the lock cylinder. I don't know if this will help. Hope so.:vs_cool:


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## raylo32 (Nov 25, 2006)

I had no problem removing the cylinder from the old switch housing and reinstalling it into the new one. Yes, it had to be in ACC to depress the button to R&R the lock cylinder. I did that when the parts were off the truck. The only issue I have is no hard shift lock on the trans when the key is removed. Truck starts and runs fine.


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## raylo32 (Nov 25, 2006)

Well, it looks like much ado about nothing for my (lack of) steering lock issue. I have been told by folks on my GM forums that they discontinued the hard mechanical steering and trans locks with key removed after the wide spread implementation of electronic anti-theft measures. Since all my previous vehicles, including my current 2009 Toyota Tacoma had these features, I mistakenly assumed they were required. Who knew? Certainly not I!

The truck does have an interlock to prevent starting unless in Park, then a solenoid operated lock that locks the shifter unless the brake is depressed. And that is apparently still required and is fully functional. So I guess I am done with the job after all.


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## 47_47 (Sep 11, 2007)

raylo32 said:


> Well, it looks like much ado about nothing for my (lack of) steering lock issue. I have been told by folks on my GM forums that they discontinued the hard mechanical steering and trans locks with key removed after the wide spread implementation of electronic anti-theft measures.


Doesn't seem right to me. What's there to prevent a kid playing in the car to putting it in neutral?


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## raylo32 (Nov 25, 2006)

Yes, agree it still isn't right but I don't see anything not connected properly. And while not perfect it really is no different from my manual trans cars that have no transmission interlocks at all preventing one from bumping the shifters into neutral when the motor is off. But I will keep trying to get it right. I am on a couple of GM forums to hopefully pick the brains of folks that have changed these out before.



47_47 said:


> Doesn't seem right to me. What's there to prevent a kid playing in the car to putting it in neutral?


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