2006 Dodge RAM 2500 Diesel, Quad Cab, Standard Bed

It seems that I bought this truck with an intermittent HAVC issue. It has become worse, but the issue is still intermittent and testable. After starting the truck, after a few seconds, the HVAC controls should become functional. In my case they sometimes work and sometimes don't work.

Failure Mode (Odd, I know):
Vehicle is started and either idling or driving (no apparent association with uphill/downhill, bumps, braking, accelerating, etc.)
1. The AC LED goes out
2. The AC clutch disengages and the vented air starts to warm

5-10 seconds laterL
3. A chime sounds once
4. The Airbag warning light lights up
5. The vent selection **** stops working
6. The temperature control **** stops working
7. The aux power outlet stops working, the cig lighter power socket still works

The blower motor speed control **** always is functional.
I called a TIPM rebuilder about the issue and they said not to send them the TIPM, because this is not an issue that they are aware of.

 

Check the wiring diagram in the manual to see where the switch wires go. I'm always amazed at what goes through the instrument cluster.

 

Just for a simple test play with the ignition switch when in run position to see if there is any reaction

 

I have tried that as well. I was tipped off to this possibility when the seller said not to put a lot of weight on the ignition key by having extra keys on the ring. Each of my vehicles have dedicated rings anyway because I have too many vehicles. I suspect that the delear warned the previous owner of this, since all of the work and oil changes were done at the dealer according to the records. Alas, there appears to be no link however to the ignition switch using the wiggle test. A friend who also owns a RAM punches his panel and suggested I try that. So, I can tell you that had no effect either (at least not on the issue). What does possibly work is wiggling the wires under the TIPM. I haven't had a willing assistant to sit in the vehicle while I wiggle each one of the multitude of wires under there while sitting in 120 deg F truck. I can hear the compressor engage, but it's not totally reliable as the truck is too loud under the hood. What is more instantly recognizable is the LED when it lights (flickers actually).

 

Remove the tipm, flip it over and take off the connectors. The contacts may be corroded. Try to clean them up and reassemble. I had that problem once on my 04 1500, of course they called it a IPM in 04.

 

Thanks, I actually took it all apart and cleaned all of the mud out. Chrysler doesn't seal these things which is surprising.
The connectors looked good and the AC worked on my test trip, but then started to fail again. I think the problem is the wiring underneath the TIPM, so I'd like to figure out which connector contains the HVAC power.

 

The FSM will have all that info, not necessarily the easiest thing to read - but once you understand how its organized I'm sure you'll find the info you need. I grabbed a pdf copy for my 04.

 

I used a SnapOn Modis to pull the codes from the TIPM and Airbag modules. There is no check engine light for this type of failure.

Active TIPM Codes
B2215 FCM Internal Fault
B210E Battery Voltage High

• Test: Greater than 16v for 5-6 Seconds

B210D Battery Voltage Low

• Test: Less than 9v for 5-6 Seconds

B18BB Window Control Circuit Low
B191D Window Control Circuit Overcurrent
U0164 Lost Communication with HVAC Control Module

• Test: No Bus Signal for 2-5 Seconds

• Can Bus B Circuit Open or Shorted
• DTCS Related to Battery Voltage, Ignition, or VIN Messages
• ECM Not Configured or Configured Incorrectly
• A/C Heater Control
• A/C Heater Control Power and Ground

Stored TIPM Codes
C1002 Brake Pedal Switch Circuit High

• Test: The TIPM monitors the B29 Brake Lamp Switch Output Circuit for 3 minutes once the set conditions have been met (Key Off, Doors Closed). If the Primary Brake Switch Signal is still active, the stop
  lamps are disabled, and code C1002 is set. The stop lamps are reactivated when the request is present during the next key cycle.

• Faulty Brake Pedal Switch
• Brake Pedal Switch harness is open or shorted
• Brake Pedal Switch circuit poor electrical connection
• Faulty Totally Integrated Power Module (TIPM)

B165E Park Lamp Control Circuit Open

• Left Park Lamp Bulb
• Right Park Lamp Bulb
• Front Control Module
• Park Lamp Relay Control Circuit Open

Active Airbag Codes
B212D Ignition Run Only Input Circuit Open
U0164 Lost Communication with HVAC Control Module

• Test: No Bus Signal for 2-5 Seconds

• Can Bus B Circuit Open or Shorted
• DTCS Related to Battery Voltage, Ignition, or VIN Messages
• ECM Not Configured or Configured Incorrectly
• A/C Heater Control
• A/C Heater Control Power and Ground

 

I hadn't mentioned that my brake lights sometimes are stuck on after shutting down the truck and exiting the vehicle. wiggling around the Brake Pedal switch seems to fix it. That is probably the C1002.
The U0164 is probably the big issue I'm having with the AC.

I picked up the MODIS on eBay for $450 and it has a 4 channel oscilliscope, so it seems like a great tool so far.

 

For 450??? You got a steal.

No clue how to help you though. Do you have a service manual for your truck? I think getting one should be your next purchase.