Diagnostic Test

WARNING: This page is about a different car, the 2015 RAM 3500 HD and 2015 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

RADIATOR COOLING FAN MODULE OPERATION
1. Turn the ignition on.
2. With a scan tool, select Radiator Cooling Fan Relay #1 Control State to actuate the Cooling Fan (Low/High).
  Is the one Cooling Fan operating?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
  No
  - Go To 2
CHECK THE (N201) LOW/HIGH RADIATOR FAN CONTROL CIRCUIT
1. Turn the ignition on, engine not running.
2. With a scan tool, select Radiator Cooling Fan Relay 1 Control State, Toggle, to actuate the Cooling Fan (Low/High).
3. Using a 12-volt test light connected to battery voltage, probe the (N201) Low/High Radiator Fan Control circuit at the Low/High Radiator Relay terminal.
  Does the test light illuminate brightly and flash on and off during the actuation?
  
  Yes
  - Replace the Low/High Radiator Fan Relay.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (N201) LOW/HIGH RADIATOR FAN CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Disconnect the PCM C1 harness connector
  CAUTION:
  Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
2. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
3. Measure the resistance of the (N201) Low/High Radiator Fan Control circuit between the (N201) Low/High Radiator Fan Control circuit in the Low/High Radiator Relay terminal and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (N201) Low/High Radiator Fan Control circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (N201) LOW/HIGH RADIATOR FAN CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (N201) Low/High Radiator Fan Control circuit at the Radiator Fan 1 Relay connector.
  Is there continuity between ground and the (N201) Low/High Radiator Fan Control circuit?
  
  Yes
  - Repair the (N201) Low/High Radiator Fan Control circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .