Diagnostic Test

WARNING: This page is about a different variant/trim than selected.

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT DTC .
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  Are DTCs P20B9, P20BB, or P20BC active or pending?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DTC INDEX (1 OF 2) and/or DTC INDEX (2 OF 2) .
  No
  - Go To 3
CHECK THE ASD FUSED RELAY (F343) OUTPUT CIRCUIT, (A914) FUSED B+ CIRCUIT AND THE (Z909) GROUND CIRCUIT FOR A SHORT TO GROUND OR AN OPEN/HIGH RESISTANCE
1. Turn the ignition on, engine off.
2. Measure the voltage across the ASD Fused Relay (F343) Output circuit and the (Z909) Ground circuit at the DEF HCU harness connector. Then, measure the voltage across the (A914) Fused B+ circuit and the (Z909) Ground circuit at the DEF HCU harness connector.
  Was the difference of either voltage reading greater than 1.0 Volts of battery voltage?
  
  Yes
  - Repair the ASD Fused Relay (F343) Output circuit or the (A914) Fused B+ circuit for an open or short to ground, or check the (Z909) Ground circuit for an open.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE WIRE HARNESS AND CONNECTORS FOR DAMAGED
1. Turn the ignition off.
2. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the DEF HCU and the PCM.
3. Look for any chafed, pierced, pinched, or partially broken wires.
4. Look for broken, bent, pushed out or corroded terminals.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE DIESEL EXHAUST FLUID (DEF) HEATER CONTROL UNIT (HCU) FOR PROPER OPERATION
1. Replace the Diesel Exhaust Fluid (DEF) Heater Control Unit (HCU) in accordance with the service information.
2. Turn the ignition on.
3. With the scan tool, erase PCM DTCs.
4. Start the engine and run it until it reaches operating temperature.
5. Test drive the vehicle under normal operating conditions.
  NOTE:
  During cold ambient temperatures, it may be necessary to test drive the vehicle for an extended period to properly cycle the fail conditions for this DTC.
6. With the scan tool, read PCM DTCs.
  Does the scan tool display this DTC?
  
  Yes
  - Go To 6
  No
  - Test complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .