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Olds expert
Olds expert, ase certified technician
Category: Oldsmobile
Satisfied Customers: 10370
Experience:  30 years experience
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dashboard anti-theft light comes..about 7 minutes later..intermittant

Customer Question

A dashboard anti-theft light comes on and, when it does, the car will not start until it goes out, about 7 minutes later. Any idea of a cause of this intermittant issue? It has been going on for years and seems not to be getting progressively worse, ocurring maybe once in twenty-five, more often when cold.
Submitted: 5 years ago.
Category: Oldsmobile
Expert:  Olds expert replied 5 years ago.

Welcome to just I'm here to help you and your 100% satisfaction is my goal.Very likely this is caused by a faulty pass lock sensor in the ignition lock Using a scan tool checked to see if there are any trouble codes being stored in the memory let me know what you find I will be years long as it takes to solve your problem Access the Passlock sensor 3-wire White, Black and Yellow wires at the Body Control Module located near the blower motor. Turn the ignition on. Leaving the connector plugged in, check for 12 volts on the White wire and 0 volts on the Black wire. This is the power and ground provided by the Body Control Module Check for 5 volts on the Yellow wire Key On Engine Off , and a lower voltage in the crank position. Do this 3-4 times in a row. Verify the voltages are ALWAYS the same. If the voltages are not always the same, verify the BCM sends out a steady 5 volt reference on the Yellow wire, replace the lock cylinder and lock cylinder housing

There's also a relearn procedure that can be done to reprogram the body control module when there is an error in the Passlock signal

Perform a security system relearn. Let the vehicle sit for more than 10 minutes with the key off. Attempt to start the engine, leave the key in the run position monitoring the security system indicator. After 10 minutes, the security indicator will change state. Turn the key off and wait 10 seconds. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on. After the second 10 minute timer has expired, turn the key off for 10 seconds. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on. After the 3rd 10 minute timer has expired, shut the key off for 10 seconds. The security system will relearn on the 4th starting attempt and the engine should start and run

Customer: replied 5 years ago.

Your amser is very technically detailed. Without diagnostic tools, how is the lay individual to use such info? Would you suggest taking it to a repair shop with the tips you have supplied. As you outline them, it sounds as if several conditons must be met before concluding that the lock cylinder and housing should be replaced, right? And does that include a new pass lock sensor you considered as the likely culprit in the first place?


The price range of a cylinder replacement?


Also, the part about years long, I did not understand.



Customer: replied 5 years ago.

Is relearn procedure a permanent fix alternative to lock cylinder replacement? This is an intermittent issue that usually results in a start after the first 7-8 mimute wait when the dashboard lite goes out, ANYWAY, WITHOUT key left in run position. Would leaving key in run position after a time when it won't start solve or relearn anything?


Is an error in the system different from a faulty pass lock sensor?

Expert:  Olds expert replied 5 years ago.

I've said I will be here as long as it takes to solve your problem y year was a typo .

But the relearn procedure is which it do after you replace the lock cylinder or if you have an intermittent problem and just need to reset the system. If the troubled keeps coming back you most likely have a faulty pass lock sensor which will all often need replacing if this is not something you can do yourself to you would be best have it done at a repair shop

Customer: replied 5 years ago.



So, the faulty pass lock sensor is a SEPARATE issue from the lock cylinder that would need replacing assuming the voltage results from the BCM diagnostic wire tests are negative? If so, based on the information, should the cylinder replacement occur first?


After looking for stored codes, that so far has yielded no results, your first suggestion about cause was the pass lock sensor, then proceeded to prescibe a replacement of lock cylinder and its housing.


Are you saying that, even after replacing the cylinder, the issue may continue until the pass lock senser is replaced? If you suspect the sensor, then why not replace it first?


One shop did suggest the cylinder, btw, but without the diagnosis procedure you provided and without any assurance of a fix.


Got it about the relearn (reset) procedure, something that was recommended and tried once, at least partially.


The issue, remember, is a theft light, no start until it quits blinking (about 7-8 minutes) and normally starts with 2nd try, an issue that's gone on for years without getting much worse with this Olds, same as the Malibu.


Thank you for your patience and knowledge.



Expert:  Olds expert replied 5 years ago.
No I did not mean replace the lock cylinder I'm an replace the lock sensor which is in the housing , of course this is just a guess un less you want to do the testing that I suggested in the first reply , this is the most common reason for your problem though
Customer: replied 5 years ago.

Got that, cylinder replacement only after the suggested bcm tests.


As a most likely cause, would a shop consider replacement of the sensor in the housing without the entire assembly, cylinder and all, do you think, typically?


Are either of these procedures very time or labor intensive?

Expert:  Olds expert replied 5 years ago.
If I was going to replace the pass lock sensor I would replace the entire assembly and be done with it so I don't have to go back and do the job twice you're looking at about 2 1/2 hours of labor
Customer: replied 5 years ago.

If the entire assembly is replaced, with or without the BCM diagnostics (that the shop might or might not be willing to perform), would you expect the intermittent issue is solved, except possibly for resets (or relearn)?


Assembly parts cost say at $500 or more?


Based on your knowlege and experience, is this most likely cause a rare occurence, since many shops seem dumb founded?

Expert:  Olds expert replied 5 years ago.
This is a fairly common occurrence so yes I give you any better than average chance of solving it by just replacing the sensor I never encourage people to replace parts without proper testing but yes from my experience the sensor is the most common point of failure
Customer: replied 5 years ago.

As noted before, this issue does not seem to get worse. Is that a possibility with a probable faulty assembly like this?


If the entire ignition assembly (and key) is replaced, would the keyless entry system still work, need to be abandoned or require a reprogramming?


Checking on parts, I noticed several manufacurers of this after market item. Are there some better selections and some to avoid, in terms of quality?


I appreciate your patience and knowledge.

Expert:  Olds expert replied 5 years ago.
i would definitely stick to the original equipment from general motors ,the key less Entry will not need to be reprogrammed once you do the normal security reprogramming everything should work fine