Heated seat issue

[JohnC]

Probably not the place for this, but, it's not HD or drivetrain or 6.5 or 6.2...

Seems if I'm in too much of a hurry to turn on the seat heater after a start they get locked out until the next start. (Reboot?) As much as I hate to shut the engine down and restart it when it's cold, warming me up is more important...

If I wait till the chime stops chiming I'm OK. If I try to activate it sooner it's hit or miss. Anyone know if there's a fix?

[DmaxMaverick]

Could be the voltage is too low to keep the relay energized during a cold start. The glow plugs and intake heater are pretty hungry. Many of the PCM/BCM functions are dependent on the voltage range, and many faults can happen when they stray. Don't know why it won't work before a reboot. Perhaps the BCM is faulting the heaters, and goes into some protection mode, or something.....

Here's the fix.....
Wait for the chime to stop (what....all of 10 seconds?). The fix is free and requires no higher knowledge.

Patient: "Doctor, it hurts when I do this."
Doctor: "Don't do that."

[JohnC]

Wait for the chime to stop (what....all of 10 seconds?). The fix is free and requires no higher knowledge.

Patient: "Doctor, it hurts when I do this."
Doctor: "Don't do that."

That's not a fix; that's a "work around". Let the computer wait, not me. It's just software.

I'm looking for a different doctor...

;)

[Duramaster]

Which one of your trucks are you working on? I know there is a software issue with certain year DMAX trucks. :confused: :confused:

[trbankii]

That's not a fix; that's a "work around". Let the computer wait, not me. It's just software.

Except that if it is in fact lacking the power to keep the relay closed then it is a bit harder to "fix" by reprogramming... ;)

[JohnC]

Duramaster: It's the '06.

Trbankii: I just don't want it to lock them out. I'd gladly push the button again later if it would do any good. Problem seems to be if I push the button before it finishes the self test it locks them out. Just repeat the test before locking out...

[Rabbler]

Do the Dmax trucks have the smart charging systems like some of the gas trucks and cars do? ( Electronic Power Management & Regulated Voltage Control (EPM & RVC) I know those systems can decrease or even disable heated accessories (Heated seats, mirrors and r defrost) if the batteries are weak or the charging system isn't up to the task.

[trbankii]

Ah, I understand now. I was thinking that if it doesn't have the power to keep the relay "locked" there isn't much that can be done - but that it then locks you out of any future attempts when the power may be back up... That is sort of ridiculous.

[JohnC]

Happened again this AM. I was sure I'd waited long enough...

[Duramaster]

Here are two things to check........... 1) is the software current in the DSM? There is a bulletin for the intermittent heated seat inop. 2) are there any DTC's setting in the DSM? DSM = Driver Seat Module. You will need a GM Tech2 and a CANdi module for this particular diagnosis. ;)

[JohnC]

Codes IN the DSM? what's it got, it's own processor? Maybe we have gone too far...

Anyhow, it's going to the dealer Thursday for the atf leak. I'll let you know...

[JohnC]

The dealer fixed the trans leak but couldn't duplicate the issue with the seats. I tried to demonstrate it, and it seemed to work just fine. Who would have guessed?

Now I think maybe I missed the point. I now think it fails when the temperature is very cold. Coincidentally, the colder it is the faster I go for the button... It ALWAYs works after one restart. One day I drove for 2 miles and it doidn't work the whole time. :shrug: :confused:

[madmatt]

sounds like a logic lock,, If it's under warranty they sould at least make sure all the software is up to date. Did they even check for bulletins???

[JohnC]

Did they even check for bulletins???

They said they did....

Maybe I threw them off track with too much information.

[madmatt]

I dropped an email to someone who may be able to help,,,, I'll let you know if he comes up w/ anything.

[madmatt]

Subject: Intermittent Heated Seats Inoperative, DTC B3941 Set (Reprogram Driver Seat Module) #05-08-50-008 - (08/19/2005)



Models: 2003-2005 Cadillac Escalade, Escalade ESV, Escalade EXT

2003-2005 Chevrolet Avalanche, Silverado, Suburban, Tahoe

2003-2005 GMC Sierra, Yukon, Yukon XL, Yukon Denali

All with Seat FRT, Individual (Non BKT) (RPO AN3)

2003-2005 HUMMER H2 with Seat, Front Bucket Deluxe (RPO AR9)

[JohnC]

Bummer... it's an '06 :(

[madmatt]

dang,,, didn't see that. I'd try a reprogram anyways. It's better then nothing.

[Duramaster]

How about any intermittent codes in the DSM. Heater element problems (codes) will turn off the heater as well as a chafed wire harness at the base of the seat where it plugs into the body harness. Move seat all the way forward and look under the rear of the seat for the harness. Look for chafes and repair as needed.

[Duramaster]

BETTER YET!!!!!!!! Please don't tell me you have an I-POD or MP3 interface device plugged into you vehicle wiring harness in anyway?!?!?!?!?!??????????!!!!!!!!!!!!!!!!!!!! :confused: If so, you might need a little beating! :D