Door Ajar Switch and 4x4 Flashing

[BlackCoffee]

I have two problems that seem related, but don't know why. The radio won't turn off when the key is removed and door opened. The chime does not work for lights or key. This seems like the door alarm switch on the driver's door. But there is more. The seat adjust and exit does not work. The seat moves with the button but not the automatic feature. Finally, I am getting a flashing 4x4 High and 4x4 Low for the transfer case.

All this appears to go away after warm up. Also, it usually occurs after an overnight shutdown in the morning, but not too much during the day.

 

[Hamfisted]

Yes, that first issue is classic symptoms of a bad door jamb switch. Some people have had some luck with spraying WD-40 or a foaming degreaser into the door latch and getting the switch freed up and working, you can try that. But at the age of the Expy it's more likely the switch has just worn out and needs to be replaced. You need to take off the door interior panel and remove the screws there on the end of the door that secure the door latch in place. Get the door latch free and rotate it into the open area where you can get to the door jamb switch there on it's bottom. Turn the switch a quarter turn to unlock it and it'll drop from the latch.
The flashing 4x4 lights might indicate an issue with the transfer case shift motor module. There should be some codes stored in the computer relating to the transfer case issue. Get a code reader for that.




https://www.rockauto.com/en/catalog...ectrical-switch+&+relay,door+jamb+switch,4360

 

[BlackCoffee]

Thanks Hamfisted, I knew you would weigh in on this problem. I just put the new door ajar sensor in. Let me get a few cold morning before I know it is fixed.

As for the 4x4 flashing. I checked and no primary or secondary codes are set. The other interesting thing is that when I get rid of the seat/door sensor problem, the transfer case problem goes away. More facts, when I did (maybe still do) have the seat/radio/door sensor problem, the system check says it can't communicate with the DSM. I noticed from the electrical diagrams that the door switch feeds the Vehicle Security Module (VSM) and the door ajar is sent via the UBP network. Have you ever heard of the door sensor taking down the network? If the network is not working, does that mean the there is a comm problem with the transfer case even though the motor works? The motor, and indications work fine when I don't have the network problem.

Not getting ahead of myself, but if it is the VSM, have you ever replaced one and how difficult is it. I'm going to look it up in the OEM shop manuals, but I don't have all the tech data on it.

Thanks,

Have a good Veteran's Day

 

[Hamfisted]

Well I think you'll find that you've fixed the door jamb switch issue. I would clear all the codes and see if anything comes back. Hopefully you've exorcised all the demons out of it !

Happy Veterans Day to you too ! ( US Navy '83-'93 )

 

[BlackCoffee]

Thanks, AF Spec Ops 1982-2002 Retired at 20.

 

[BlackCoffee]

Finally, I may have the solution. It looks like a bad DEATC was taking out everything on the UDP buss. Indications got worse and consistent. Finally, advance track wouldn't come on. I was suspicious of the VSM, but starting looking at other boxes on the network. I had a spare EATC that I picked up when they were discontinued. Glad I did. Put the new box in, got rid of all the errors. Put the old box in and they came back. I'll give it some time, but it looks like I may have solved all the problems. Bad UDP network.

 

[USAF Sarge]

Thanks, AF Spec Ops 1982-2002 Retired at 20.

Retired Air Force also, did 17 of my 23 years in AFSOC. Was with 7th SOS, 39th SOW and the 711th SOS and 5th SOS, 919th SOW. Did Aircrew Life Support for the MC-130E Combat Talon and MC-130 N/P Combat Shadow.

 

[BlackCoffee]

Retired Air Force also, did 17 of my 23 years in AFSOC. Was with 7th SOS, 39th SOW and the 711th SOS and 5th SOS, 919th SOW. Did Aircrew Life Support for the MC-130E Combat Talon and MC-130 N/P Combat Shadow.

See you on on the Straygoose page. Go Maynard!