Diagnostic Test

DTC IS ACTIVE
1. Turn the ignition on.
2. With a scan tool, View DTCs.
3. Record all DTC information.
  NOTE: If DTC U1008 LIN 1 BUS is active in addition to this DTC, perform the diagnostic procedure for that DTC before continuing with this test.
  
  NOTE: If DTC U1132 GENERATOR COMMUNICATION is active or stored in addition to this DTC, proceed with this diagnostic procedure.
4. With a scan tool, Clear DTCs.
5. Start the engine and allow it to reach normal operating temperature.
6. Monitor the scan tool for at least 2 minutes.
7. With a scan tool, View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to step 2
  No
  - Refer to the INTERMITTENT CONDITION Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure
U1132 GENERATOR COMMUNICATION DTC IS PRESENT
1. With a scan tool, View DTCs.
  Is DTC U1132 GENERATOR COMMUNICATION Active in addition to this DTC?
  
  Yes
  - Go to step 3
  No
  - Go to step 4
(D509) LIN BUS CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Generator harness connector.
3. Disconnect the Glow Plug Module harness connector.
4. Disconnect the Engine Control Module (ECM) harness connector.
5. Measure the resistance of the (D509) LIN Bus circuit between the Generator harness connector and the Engine Control Module (ECM) harness connector.
6. Measure the resistance of the (D509) LIN Bus circuit between the Glow Plug Module harness connector and the Engine Control Module (ECM) harness connector.
  Is the resistance below 10.0 ohms for both measurements?
  
  Yes
  - Go to step 7
  No
  - Repair the (D509) LIN Bus for an open circuit or high resistance.
  - Perform the ECM Verification Test. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure
(D509) LIN BUS CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Glow Plug Control Module harness connector.
3. Disconnect the Engine Control Module (ECM) harness connector.
4. Measure the resistance of the (D509) LIN Bus circuit between the Glow Plug Module connector and the Engine Control Module (ECM) connector.
  Is the resistance below 10.0 ohms?
  
  Yes
  - Go to step 5
  No
  - Repair the (D509) LIN Bus for an open circuit or high resistance.
  - Perform the ECM Verification Test. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure
(Z921) GLOW PLUG CONTROL MODULE GROUND CIRCUIT OPEN OR HIGH RESISTANCE
1. Ignition off.
2. Measure the resistance between ground and the (Z921) Glow Plug Control Module ground circuit at the Glow Plug Control Module harness connector.
  NOTE: If the Glow Plug Control Module loses it's ground path, the module will ground through one of the Glow Plugs. This can cause the Glow Plug to fail. After repairing the ground circuit be sure to clear all DTCs and cycle ignition several times. If any Glow Plug DTCs become active, perform the diagnostic procedure for the appropriate Glow Plug.
  
  Is the resistance below 10.0 ohms?
  
  Yes
  - Go to step 6
  No
  - Repair the (Z921) Glow Plug Control Module ground circuit for an open circuit or high resistance.
  - Perform the ECM Verification Test. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure
GLOW PLUG CONTROL MODULE
1. Ignition off, engine not running.
2. Connect the Engine Control Module (ECM) harness connector.
3. Replace the Glow Plug Module in accordance with the Service Information.
4. Turn the ignition on.
5. With a scan tool, Clear DTCs.
6. Start the engine and allow it to reach normal operating temperature.
7. Monitor the scan tool for at least 2 minutes.
8. With a scan tool, View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to step 7
  No
  - Test Complete.
  - Perform the ECM Verification Test. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure
ENGINE CONTROL MODULE (ECM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Glow Plug Module and the Engine Control Module (ECM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Refer to any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the ECM Verification Test. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure
  No
  - Replace the Engine Control Module (ECM) in accordance with the Service Information.
  - Perform the ECM Verification Test. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure