Diagnostic Test

DTC IS ACTIVE
NOTE: Diagnose and repair any system voltage or ASD Relay DTCs before continuing with this test.
1. Ignition on, engine not running.
2. With the scan tool, Clear DTCs in the Engine Control Module (ECM).
3. With the scan tool, actuate the Glow Plugs.
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 step 2
  No
  - Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure
FUSED ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Glow Plug Module harness connector.
3. Turn the ignition on.
4. Using a 12 volt test light connected to ground, check the Fused ASD Relay Output circuit in the Glow Plug Module harness connector.
  NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go to step 3
  No
  - Repair the Fused ASD Relay Output circuit for an open circuit or high resistance.
  - Perform the ECM Verification Test. See DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure
GROUND CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Using a 12 volt test light connected to B+, check the Ground circuit in the Glow Plug Module harness connector.
  NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go to step 4
  No
  - Repair the 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 MODULE
1. Replace the Glow Plug Module in accordance with the Service Information.
2. Turn the ignition on.
3. With the scan tool, Clear DTCs.
4. With the scan tool, actuate the Glow Plugs.
5. Monitor the scan tool for at least two minutes.
6. With the scan tool, select View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to step 5
  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 SYSTEM WIRING DIAGRAMS 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. 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