Diagnostic Test

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

ACTIVE DTC
1. Turn the ignition on for one minute, engine not running.
2. With the scan tool check for active DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION. Refer to INTERMITTENT CONDITION .
CHECK THE DEF TANK HEATER SUPPLY CIRCUIT FOR A SHORT TO GROUND
1. Turn ignition off.
2. Disconnect the DEF Supply Pump assembly harness connector.
3. Disconnect the DEF Dosing Control Unit C2 harness connector.
4. Measure the resistance between ground and the DEF Tank Heater Supply circuit at the DEF Supply Pump assembly harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the DEF Tank Heater Supply circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE DEF TANK HEATER SUPPLY CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the DEF Tank Heater Supply circuit between the DEF Supply Pump assembly harness connector and the DEF Dosing Control Unit C2 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the DEF Tank Heater Supply circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE DEF TANK HEATER RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the DEF Tank Heater Return circuit between the DEF Supply Pump assembly harness connector and the DEF Dosing Control Unit C2 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the DEF Tank Heater Return circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
DIESEL EXHAUST FLUID TANK HEATER
1. Reconnect the DEF Dosing Control Unit C2 harness connector.
2. Connect a jumper between the DEF Tank Heater Supply circuit and the DEF Tank Heater Return circuit at the DEF Supply Pump assembly harness connector.
3. Turn ignition on.
4. With a scan tool, View DTCs.
  Does the scan tool display DTC P202C as active or pending and P202B as stored with the jumper in place?
  
  Yes
  - Replace the DEF Supply Pump assembly in accordance with the service information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the DEF Dosing Control Unit in accordance with the service information. Refer to UNIT, DIESEL EXHAUST FLUID DOSING CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .