Not sure what his problem is, but it isn't the PassLock that is preventing the engine from cranking. The only thing PassLock does is stop the ECM from opening the injectors. The engine will crank with a PassLock issue. Curious about what the real fix would be for his problem. Maybe an ignition switch. Maybe BCM.

 

I'm having a no crank no start issue and something draining my battery with my 08 Colorado. I replaced the starter and the ignition switch and still no crank no start. My pass lock light goes solid until I turn key to start then it continuously blinks. Any idea what the problem could be?

 

^^^Agree^^^

Guessing it's either coincidental w/the son's jump-start action, or the son's not being 100% honest w/what happened when truck was borrowed.

Either way...this is probably ignition related - bad switch. Had mine replaced last fall for similar problem.

 

Thanks Iceman, can you describe the symptoms of your bad switch? The symptoms on mine is that all accessories start, but when you try to crank it the dash lights blinks a little bit and then nothing, no crank... funny thing is that if I wait 10 exact minutes the truck starts right away with no issues.

 

Sorry...didn't see this question until today. When my Passlock failed, I was experiencing the good 'ol crank/no-start w/flashing lock deal and it hasn't returned since I cut the control wire...going on 5-6 years now.

For the ignition, there were times when my radio wouldn't come on (dead), the the gauges/dash would light-up, but everything was dead (no needles worked/moved). The truck always started, but other electronics were hit/miss. Thought it might be one of the control modules, or wire short so ended up taking to local GM shop where they traced it to the ignition. Since replaced...no more issues.

For you, it could be a combination of Passlock & ignition...electrical gremlins suck. Hope you get yours fixed.

 

...and its because the 10 minute wait to start the truck that I thought it was related with passlock...

 

I've been dealing with the exact same issue as fitsector and also thought it was the passlock system, would love to know what the problem actually is

 

Things are a bit confused. fitsector may indeed have a PassLock issue. That hasn't been ruled out. What is being questioned is the subject of the video. The person making the video seems to think that the problem he is experiencing is related directly to the PassLock system, but the fact that the engine will not turn over indicates that the problem is something else. No Passlock problem will prevent the engine from cranking.

If, when cranking the engine, the security light is flashing, that indicates a PassLock problem. The engine may initially start and run until the BCM gets the message to the ECM to deactivate the injectors. Once the ECM has deactivated the injectors, on subsequent starts the engine will still turn over, but no ignition will take place.

There is an Owner's Manual procedure to wait 10 minutes and retry. That will work sometimes.

 

Re. “…but the fact that the engine will not turn over indicates that the problem is something else.” This is not always going to be be correct. Apparently with some years, the engine will crank and it will not start when you are locked out with the passlock. On my 2009 Hummer H3 the engine would not even turn over. The battery was fine. The red lock icon was flashing. I followed the relearn procedure and the lock icon remained lit steadily, and the vehicle started without issue. it has been starting fine all day today. I expect this problem to return. I will likely end up replacing the passlock sensor. I do not know if my Innova 5610 will reveal any issues. Will likely connect over the weekend in an effort to find out. It does appear that in some instances the only thing that’s shut off is fuel, but there are definitely other instances where there is a no-crank condition as a direct result of the passlock being triggered.

 

update to this... Before I could even try the procedure explained in the video... I took the spare key that came with the truck (brand new never used key) and this issue went away... Its been 4 days since I replaced the 8 years old key for the new one and I haven´t had any single event again.

Maybe its related with the worn key that is not making properly contact with the ignition switch and the truck is getting confused with all the anti theft systems....

I´ll post any update if the conditions on my truck changes.

 

That's good news! I've heard of a couple of other PassLock problems that were fixed by replacing the key.

 

Follow up to this problem. Yesterday truck started to do the same fucking problem, now even when using the new key. Might be the ignition switch.
Damm it! love to have this bugs on my trucks. They have been so reliable for so many years. hope to find the problem soon

 

Has anybody resolved the passlock flashing - no start issue. I have been dealing with this issue for years! I've changed the passlock sensor on the ignition switch, that didn't fix it. I've not tried getting new keys cut yet but the guy above said that didn't fix it either. I really don't want to cut the passlock wire and look at the dash light forever but I hate waiting 10 minutes to start also. My wife now drives the truck to work and has been late a couple times thanks to the damn Colorado not starting.

 

I had my Passlock removed with a custom tune. Worth every penny not having to worry about the possibility of getting stuck.

Contact Supermodulation and setup a game plan.

 

Thanks WV NATIVE, I will look into a custom tune and have Passlock removed. I sure would hate to sell the truck because its making my wife late for work. I guess I could have her wake up every morning exactly 10 minutes early to see if the truck will start. lol. I do have a spare key, I will probably try that approach first. Sounds like its worked for a few people, but others it has not.

 

Back in '04 my brand new truck also had an intermittent no crank issue but it would usually start eventually. After two or three trips back to the dealer over two months it was finally fixed with a replacement battery.

 

Easiest fix = cut the blue/white wire (search How To for steps). One caution, need to make sure truck is running BEFORE you cut the wire...

 

Passlock will also disable the starter...

Not sure why it's been decided that that's not the case.

The starter disable is also not something that can be "tuned out"... Because it's BCM related.

The only fix for this is the "wire cut" method (or other wired in passlock bypass method)... Or to make sure all components of the ignition system are in perfect working order.

 

Passlock will also disable the starter...

Not sure why it's been decided that that's not the case.

The starter disable is also not something that can be "tuned out"... Because it's BCM related.

The only fix for this is the "wire cut" method (or other wired in passlock bypass method)... Or to make sure all components of the ignition system are in perfect working order.

 

From the 2006 GM Service Manual:

Vehicle Theft Deterrent Description and Operation:

ECM function:

The engine control module (ECM) contains the remainder of the logic of the theft deterrent system. If a serial data message containing a valid password is received from the body control module (BCM), the ECM will continue to allow the fuel injectors to operate. The ECM will allow the fuel injectors to operate until it decides there is no valid password coming from the BCM. If the ECM does not receive a serial data message, or receives a serial data message with an incorrect password, the engine will crank and will not run or will start and stall immediately.

 

This little tidbit is relevant.

The engine control module (ECM) contains the remainder of the logic of the theft deterrent system.

 

Although the BCM is considered the master control module, it has no direct control of engine functions. The ECM determines what actions to take when A PassLock signal, valid or not, is received from the BCM.

 

That is incorrect in regards to the 355.

The 355 is one of few platforms the the Starter Signal comes from the BCM.

 

I had the same issue, it was passlock, the lock blinked on my screen just as described for all other passlock people. It never turned over, never tried to do anything. I replaced the ignition switch, relearned the key, and it's been fine since. Anyone saying that the truck will turn over or it has to be something else is not correct on every model. Mine was an 08, and never turned over.

 

Keep in mind that a defect in the ignition switch can affect more than one circuit. It could have disabled both the PassLock and the start circuit at the same time.

 

Not going to argue about the operation of the PassLock System

From the 2006 GM 355 Service Manual. Accept it or not, makes no difference to me:

The Passlock™ system is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate. The Passlock™ controller reads the coded Passlock™ data signal. The data consists of a voltage generated by a voltage divider network created between the Passlock™ assembly and the Passlock™ controller. If the data is correct , indicating rotation of the lock cylinder with the proper mechanically cut key, then the Passlock™ controller sends a password to the powertrain controller via serial data to indicate that fuel should be delivered to the engine. The Passlock™ controller also interfaces with the driver displays subsystem to indicate, via a security telltale, the Passlock™ subsystem status and acute subsystem failures.

The components of the Passlock™ system are as follows:

• The ignition switch

• The body control module (BCM)

• The security indicator on the instrument cluster

• The engine control module (ECM)

Ignition Switch
The ignition switch contains the wiring and electrical switching portion of the column mounted ignition assembly. The ignition switch includes wiring pigtails which connect it to the base of the column connector. The Passlock™ sensor is an internal resistor within the ignition switch.

The ignition switch receives a 5-volt reference from the body control module (BCM) via the ignition key resistor signal circuit. When in the start position, the 5-volt reference travels through the Passlock™ sensor within the ignition switch. This creates a unique voltage value which is returned to the BCM via the off/run/crank voltage circuit.

Body Control Module (BCM)
The body control module (BCM) contains the logic of the theft deterrent system. The BCM provides the 5-volt reference to operate the Passlock™ sensor. The BCM also measures the voltage of the off/run/crank voltage. The voltage measured will indicate whether the Passlock™ sensor has been activated and whether the resistance value from the sensor is a valid value or the tamper value. If voltage measured is in the valid range, the BCM compares this voltage to a previously learned voltage code. If the voltage codes match, the BCM sends a serial data message containing a password to the engine control module (ECM). If the voltage codes do not match, or the voltage is in the tamper range, or there is a circuit fault, the BCM will not send the correct password to the ECM, and the vehicle will not start.

Engine Control Module
The engine control module (ECM) contains the remainder of the logic of the theft deterrent system. If a serial data message containing a valid password is received from the body control module (BCM), the ECM will continue to allow the fuel injectors to operate. The ECM will allow the fuel injectors to operate until it decides there is no valid password coming from the BCM. If the ECM does not receive a serial data message, or receives a serial data message with an incorrect password, the engine will crank and will not run or will start and stall immediately.

 

You are 100% right got my 07 avalanche to crank over after adding 5v resistor to pigtail going to BCM

 

I just bought a GMC Canyon 2019 with 13,000 miles 3 days ago. Today I was stranded with my son when my GMC locked me out because of the anti-theft passcode. This was my 3rd day of ownership. I was waiting for my son in front of his school when it locked me out and refused to start. I called my local GMC and they walked me through the 10 minute wait trying to reset the code. After 3 hours the tow truck had to be called. As I am typing this, my truck is sitting in the GMC dealership waiting to be serviced. I will never buy another GMC product. I should have bought that Toyota Tacoma. After 3 days of ownership already thinking of trading it in. The CEO's at GMC really don't care about their customers or their products. Apparently from what I'm reading this has been a problem for years that they have never taken care of. Now I understand what GMC really stands for - Garbage Motor Company.

 

I get your frustration. However, If you believe that different car manufacturer's treat customers better than others after a vehicle sale I would say no they don't. It's the specific dealership where you find the difference. I hope you get a good resolution to your problem.

 

I replaced the Passlock sensor (purchased on ebay). Issue has gone away. There is a 30 minute reset procedure for truck to learn new sensor.

 

This worked on my 2008 Colorado. Amazing!! Thanks.

 

Omg I've been having some problem for months no way this works

 

Welcome to the Nation.

If that video doesn't solve your issue, come back and start a new Thread and we will address the problem.