Diagnostic Test

WARNING: This page is about a different car, the 2015 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.

DTC IS ACTIVE
NOTE:
If DTCs P20B9, P20BB, or P20BC are present, perform the Diagnostics for those DTCs before continuing with this one.

NOTE:
If there are any DEF Pump DTCs present, perform the Diagnostics for those DTCs before continuing with this one.
1. Ignition on, engine not running.
2. With the scan tool, erase DTCs in the PCM.
3. Start the engine and allow the engine to reach normal operating temperature.
4. Monitor the scan tool for at least two minutes.
5. With the scan tool, select View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT DTC .
CHECK THE (F343) ASD SUPPLY CIRCUIT AND THE (Z909) DEF HCU GROUND CIRCUIT FOR A SHORT TO GROUND OR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the DEF HCU harness connector.
3. Turn the ignition on, engine off.
4. Measure the voltage across the (F343) ASD Supply circuit and the (Z909) DEF HCU Ground circuit at the DEF HCU harness connector.
  Was the voltage the same as battery voltage (+- 1.0 Volt)?
  
  Yes
  - Replace the DEF Tank in accordance with the service information.
  - Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
  No
  - Repair the (F343) ASD Supply circuit for an open or short to ground, or check the (Z909) DEF HCU Ground circuit for an open.
  - Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .