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JimY 06-02-2019 06:29 PM

Occasional Security light, ODOM deduct, P1629 code while runs
2002 VUE AWD V6 Auto Trans, ABS, about 290,000 miles. And twice, recently, all doors lock and gages, electric power steering & dome lights go dead...still running...key fob and door lock switches will not work. And once, 2 weeks ago, after <3 minute run on a hot day, with engine off but key not yet removed, all doors locked on their own and would not start. I ran battery nearly dead trying to start it. After 1 hour wait it started but I ran it only 1~2 minutes because tow truck was arriving. Repair shop found low/week battery & could not find any problem after new battery in. (NOTE: Battery exchange by shop would have reset the BCM. Don't know if they searched factory codes before clearing.) Got my own good scanner yesterday and saw P1629 for 1st time. Cleared that code, then did some restarts. IGN key wiggling and Pass Lock Sensor cable wiggling while running did not bring P1629 back. No further driving before this post. HISTORY: Security light blink-on, dash illumination blink-off and ODOM deduct started Oct 2018 after another shop did engine work to fix a Throttle Body malfunction and also disconnected (and cleaned, they said) firewall bulkhead connector (behind left kick panel) suggested by a TSB on the Throttle Body issue. No other symptoms all winter (cold weather?) until last 3 weeks. I checked and inside of that connector is full of dielectric grease. I've not cleaned it to look for corrosion. I can't induce the Security light symptom by wiggling cables to ignition switch and BCM while running. I've also disconnected and reconnected BCM cables and had same symptom since. I plan to test basic voltage at BCM and, if I can, while running. NOTE: Miles are stored in BCM on the VUE, not in the IPC, and given the other symptoms, I don't think it can be the IPC causing this. Am I wrong? Can this be anything but a bad ground or flaky BCM? Help locating correct ground points to clean would be appreciated? Thanks.

fdryer 06-02-2019 09:17 PM

Re: Occasional Security light, ODOM deduct, P1629 code while runs
1 Attachment(s)
Search threads about bcm connections and rain water getting into connections and causing corrosion. The bcm has Passlock and other functions like lighting, odometer storage, door locks, ect. At best, this may be connection corrosion on terminals related to the bcm. At worst, the bcm is failing. Electric power steering isn't bcm controlled as it has its own power steering control module.

A partial reprint for DTC 1629;

[I][U]Circuit Description[/U]

The powertrain control module (PCM) controls the fuel injector operation based on a vehicle theft deterrent (VTD) password from the vehicle body control module (BCM). When the ignition is first turned ON, the BCM sends a programmed theft deterrent password to the PCM. The PCM acknowledges the password and responds to the BCM that normal fuel injector operation will continue. When starting the engine, the PCM looks for a password from the BCM through the Class 2 serial data circuit. If the password is not recognized or not present, the PCM will disable the engine. If an incorrect or no password is received, fuel enable will not occur and the engine will not start. The Security indicator will flash on the instrument panel cluster (IPC) for approximately 4 seconds. If an incorrect or no password is received more than three times, this indicates that the engine is disabled for at least 10 minutes and that the Security indicator will illuminate solid on the IPC for approximately 3 seconds then flash on the IPC for 10 minutes. If the PCM loses communication with the BCM within the same ignition cycle, the vehicle will be enter fail-enable mode and continue to run on the following ignition cycles. [/I]

BCMs and ECMs are reset when battery power is removed and usually of no concern since batteries discharge from winter starting, power disconnects needed when working on electrical problems or replaced when battery life deems it necessary. Below is a copy of the electric power steering system description.

What's interesting is losing power steering, separate from bcm related issues. My initial guess is main power; battery, both battery cables and their connections (positive to fuse box and starter, two grounds - chassis and engine block). Electric power steering has its own main power connections to battery; 10 amp and 80 amp EPS fuses, wiring to battery, power steering control module, electric motor and PSCM ground.

JimY 06-04-2019 11:13 AM

Re: Occasional Security light, ODOM deduct, P1629 code while runs
Thanks fdryer. Just yesterday got wiring and connector diagrams from ALDATADIY. Will be following your suggestions. Yes, I had seen those similar threads. And was planning to do ground path and power path resistance checks and visual ground point checks. Seems like ALLDATA info will show me the correct ground points to look for. Sorry failed to mention that.

By the way, Power Steering Assist is enabled, and thus can be disabled by a crashed/faulty BCM... Yes, I agree, it is not controlled by BCM. I've only lost Assist when the BCM crashed. I've reset BC once by taking its connectors off and waiting at least 1 minute. Then restart engine and all is OK.

Does anybody have any further feedback about getting a refurbished BCM from ? Or new, or rebuilt, from anywhere else?


JimY 06-04-2019 12:26 PM

Re: Occasional Security light, ODOM deduct, P1629 code while runs
Duplicate Post by accident. Content deleted here.

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