Diagnostic Test

WARNING: This page is about a different car, the 2012 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.

CHECK IF DTC IS ACTIVE
1. Ignition on, engine not running.
2. With the scan tool, read HVAC DTC's after a minimum of 60 seconds.
  Is this DTC active?
  
  Yes
  - Go To 2.
  No
  - Go To 6.
CHECK THE (F921) FUSED IGNITION RUN CONTROL OUTPUT CIRCUIT FOR AN OPEN

Fig 1: Checking Fused Ignition Run Control Output Circuit For An Open
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off to the lock position.
2. Disconnect the Infrared Sensor harness connector.
3. Ignition on, engine not running.
4. With a test light connected to ground, check the (F921) Fused Ignition Run Control Output circuit.
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Go To 3.
  No
  - Repair the (F921) Fused Ignition Run Control Output circuit for an open.
  - Perform HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
CHECK THE (C83) IR SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND

Fig 2: Checking IR Sensor Signal Circuit For A Short To Ground
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off to the lock position.
2. Disconnect the A/C Heater Control C1 harness connector.
3. Measure the resistance between ground and the (C83) IR Sensor Signal circuit.
  Is the resistance below 100k Ohms?
  
  Yes
  - Repair the (C83) IR Sensor Signal circuit for a short to ground.
  - Perform HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Go To 4.
CHECK THE (C83) IR SENSOR SIGNAL CIRCUIT FOR AN OPEN

Fig 3: Checking IR Sensor Signal Circuit For An Open
Courtesy of CHRYSLER GROUP, LLC
1. Measure the resistance of the (C83) IR Sensor Signal circuit between the A/C Heater Control C1 harness connector.
  Is the resistance below 100k Ohms?
  
  Yes
  - Repair the (C83) IR Sensor Signal circuit for an open.
  - Perform HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Go To 5.
CHECK THE INFRARED SENSOR
1. Replace the Infrared Sensor in accordance with the Service Information.
2. Perform HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  Did the DTC reset performing the HVAC Verification Test?
  
  Yes
  - Replace and program the A/C Heater Control in accordance with the Service Information.
  - Perform HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Test complete.
CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, partially broken wires.
4. Check the connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals.
5. Wiggle the wiring and connectors while checking for shorted and open circuits.
6. With the scan tool, check the Environmental Data to help identify the conditions in which the DTC was set.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  No
  - Test complete.