DATC malfunction causes "passenger door ajar" message

[n8bachelor]

Need some tips here. 2006 LS with odd electrical malfunctions.

Press passenger window down switch and the "passenger door ajar" message comes up with the message center beep. Window functions abnormally and I've had to pull it up a few times. Message goes away once the switch is released.

Press the "auto" button on DATC and the message center beeps with error "passenger door ajar" interior lights come on and the hvac does not operate. No heat, no cold, no fan, nothing. Only get the message when activating the hvac or the passenger window.

Ran the DATC self check but no codes came up. I did smell some hot electronic smell when it finished though. Possibly something burning out or a short?

Anyone ever had passenger door ajar message in conjunction with hvac failing to operate? Could it be a bad DATC? Wouldn't that pull up a code on the self check though?

Taking things apart now to look for shorts or burned wires. Nothing so far in the passenger door.

 

[n8bachelor]

I took out the DATC and radio but did not see anything amiss. No shorted wires or burning that I could see. Put it back together and ran the DATC self test again but it came back clear. Same error and non-functional hvac system. Any ideas before I replace the DATC unit?

 

[joegr]

Well, you could try the car with the DATC removed. If everything else seems to work okay, including the passenger window without triggering a door ajar message, then maybe it is the DATC.
Otherwise, I suspect a problem on the CAN bus. It could be a wiring short, or more likely a failure in one of the many electronic modules that connect to the CAN bus. A good scan tool that can read Ford specific codes from all the modules might give a good clue on the problem.

 

[1LoudLS]

are we talking about the drivers door passenger window switch, the passenger door window switch, or does it happen with either switch?

 

[n8bachelor]

are we talking about the drivers door passenger window switch, the passenger door window switch, or does it happen with either switch?

Same result from either switch. I have this week off and will look into it further.

 

[n8bachelor]

Well, I disconnected the DATC and the problem persists. Either switch to roll down the passenger window causes the door ajar alarm to trip and no movement in the window. There is some noise from the passenger door window motor but I suspect it shorts out before actually rolling the window. The door ajar alarm is only active as long as the switch is pressed or the HVAC system is switched to ON. I can live without the passenger window but need to get some heat going.

Is there any way to narrow down which electronic module might be the cause of the problem prior to a diagnostic scan? During my stereo install I mounted my amp next to the REM, ran speaker wire past the driver foot well module, ran speaker wire past the passenger fuse panel, and installed sound dampener in the driver door by the FEM. The problems did NOT start until several months after the install so I'm not sure they are related. I'm pretty meticulous with my work and have found no evidence of pinched wires so far. I'm sure there are other electronic modules in this car but it might help to narrow my search to know which module controls the windows, HVAC, and message system in the car.

As an aside, the car was overheating about a year ago and I had the DCCV replaced based on the self-test codes on the DATC. The fan motor seems to run full force earlier, and more often now that it did so I suspect there may still be air in the system. Temperatures stay in line though, even through the summer. My AC compressor also needs to be replaced due to a leak. I just keep telling myself "I love my Lincoln" despite it's faults.

Any other suggestions before I take it to the Ford dealer for a diagnostic of the CAN bus and electronic modules?

 

[joegr]

The climate control module is the DATC. It has some interaction with the PCM.
Windows are controlled by the Driver's door module, the two front window smart motors, and the REM.
The message center (in the cluster) displays the messages and interacts with the REM, FEM, and PCM.
There are many modules on the CAN bus. In theory, it could be any of them, or it could just be wiring.

 

[n8bachelor]

The climate control module is the DATC. It has some interaction with the PCM.
Windows are controlled by the Driver's door module, the two front window smart motors, and the REM.
The message center (in the cluster) displays the messages and interacts with the REM, FEM, and PCM.
There are many modules on the CAN bus. In theory, it could be any of them, or it could just be wiring.

Thanks Joe. I'm going to pull the driver door cover to inspect the wiring there before taking it in. I sure don't like the idea of chasing down a wiring short if diagnostic does not point to a specific module as faulty.

 

[joegr]

Be warned that this will be more than just pulling DTCs. They'll have interrogate each module.

 

[n8bachelor]

Be warned that this will be more than just pulling DTCs. They'll have interrogate each module.

Yeah, I'll need to properly convey that to the tech taking the service order. It will be an interesting write-up to convey the issues and explain what I'm asking them to do.

 

[n8bachelor]

Thanks Joe. I'm going to pull the driver door cover to inspect the wiring there before taking it in. I sure don't like the idea of chasing down a wiring short if diagnostic does not point to a specific module as faulty.

Well, I took the driver door panel off to inspect the wiring. Unplugged the Driver Door Module and inspected all wiring plugs and any wires not wrapped in gaffer tape. Nothing looked amiss with the wires or plugs. Put it back together and headed to the dealership to set up an appointment and wouldn't you know the damn heater worked. Hot air, full fan control, and the passenger window worked too. Rolled it down and back up quickly just in case. Took it to the carwash instead of the dealership, drove around town a little, and the HVAC continued to work all the way home (total drive time 30 minutes). Pulled into my driveway and hit the DS passenger window switch again and the whole thing crapped out again. Back to the same beeping, door ajar message, and non-functioning HVAC and PS window.

I would not think pulling the power wires on the DDM would do anything different than removing the battery wire (which I did when removing the DATC) but I guess it could have reset something faulting in there. I'm leaning toward a shorting wire in the driver door somewhere. I'll give it another try tomorrow to see if I can replicate the results.