Diagnostic Test

WARNING: This page is about a different car, the 2013 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.

TEST FOR INTERMITTENT CONDITION
NOTE:
Check for any TSB(s) related to the condition. If a TSB applies, perform the procedure outlined in the TSB before continuing.
1. Turn the ignition on.
  NOTE:
  Make sure the IOD fuse is installed and battery voltage is between 10.0 and 16.0 volts.
2. With the scan tool, read the module status.
  NOTE:
  Check the BCM for any active CAN hardware DTCs, perform DTC before proceeding.
  
  Does the scan tool indicate that the module is active on the bus?
  
  Yes
  - The no response condition is not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
  No
  - Go To 2
CHECK THE FUSED B(+) CIRCUIT FOR AN OPEN OR SHORT

Fig 1: Using 12-volt Test Light Connected To Ground To Check Fused B(+) Circuit
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the A/C Heater Control harness connector.
3. Using a 12-volt test light connected to ground, check the Fused B(+) circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 3
  No
  - Repair the open or short in the Fused B(+) circuit.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE GROUND CIRCUIT FOR AN OPEN

Fig 2: Using 12-volt Test Light Connected To 12-volts To Check Ground Circuit
Courtesy of CHRYSLER GROUP, LLC
1. Using a 12-volt test light connected to 12-volts, check the Ground circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 4
  No
  - Repair the open in the Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE FUSED RUN RELAY OUTPUT CIRCUIT FOR AN OPEN OR SHORT

Fig 3: Using 12-volt Test Light Connected To Ground To Check Fused Run Relay Output Circuit
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition on.
2. Using a 12-volt test light connected to ground, check the (F921) Fused Run Relay Output circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 5
  No
  - Repair the open or short in the Fused Run Relay Output circuit.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE CAN INTERIOR BUS (125K) CIRCUITS FOR AN OPEN

Fig 4: Measuring Resistance Of CAN Interior Bus (-)/(+) Circuit Between TIPM Harness Connector And HVAC Harness Connector
Courtesy of CHRYSLER GROUP, LLC
1. Measure the resistance of the (D264) CAN Interior Bus (125K) (-) circuit between the BCM harness connector and the A/C Heater Control harness connector.
2. Measure the resistance of the (D265) CAN Interior Bus (125K) (+) circuit between the BCM harness connector and the A/C Heater Control harness connector.
  Are the resistances below 5.0 Ohms?
  
  Yes
  - Replace the A/C Heater Control Module in accordance with the Service Information. Refer to CONTROL, A/C AND HEATER, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Repair the open in the CAN Interior Bus (125K) circuit.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .