P0673-CYLINDER 3 GLOW PLUG CIRCUIT OPEN
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For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Glow Plug Module has the appearance of a large relay and is located next to the battery. The Glow Plug Module receives a signal from the Powertrain Control Module (PCM) to activate the Glow Plugs. The Glow Plug Module supplies power to the Glow Plugs and a ground path is provided through the body of the Glow Plugs. The Glow Plug Module communicates with the PCM over the (K330) Glow Plug Module Control circuit.
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When Monitored:
Continuously with the ignition on and the Glow Plugs commanded on.
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Set Condition:
The PCM detects an open on the Cylinder 3 Glow Plug circuit.
Possible Causes |
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| (A204) GLOW PLUG 3 CONTROL CIRCUIT OPEN/HIGH RESISTANCE |
| GLOW PLUG 3 |
| GLOW PLUG MODULE |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| 1. | Ignition on, engine not running. |
| 2. | With the scan tool, erase DTCs in the PCM. |
| 3. | Perform several ignition cycles leaving the ignition on for at least 10 seconds then off for 10 seconds. |
| 4. | With the scan tool, read the PCM DTCs. |
Did this DTC return?
Yes
- Go To 2
No
- Perform the INTERMITTENT DTC diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2. CHECK THE (A204) GLOW PLUG 3 CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
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| 1. | Turn the ignition off. |
| 2. | Disconnect the Glow Plug 3 harness connector. |
| 3. | Disconnect the Glow Plug Module harness connector. |
| 4. | Measure the resistance of the (A204) Glow Plug 3 Control circuit between the Glow Plug 3 harness connector and the Glow Plug Module harness connector. |
Is the resistance below 5.0 Ohms?
Yes
- Go To 3
No
- Repair the (A204) Glow Plug 3 Control circuit for an open or high resistance.
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Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
| 1. | Turn the ignition off. |
| NOTE: | Be sure to zero the meter before taking the following measurement. |
| 2. | Measure the resistance of Glow Plug 3. Measure between the Glow Plug threaded terminal and a good chassis ground if the Glow Plug is installed in the Cylinder Head. If the Glow Plug is out of the Cylinder Head, measure between the Glow Plug threaded terminal and the body of the Glow Plug. |
| NOTE: | The resistance through a good Glow Plug should be between 0.2 Ohm and 5.0 Ohms. Any reading above or below these parameters indicates an open or shorted Glow Plug. |
Does the resistance through the Glow Plug read between 0.2 Ohm and 5.0 Ohms?
Yes
- Go To 4
No
- Replace the Glow Plug in accordance with the service information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| 1. | Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Glow Plugs and the Glow Plug Module. |
| 2. | Look for any chafed, pierced, pinched, or partially broken wires. |
| 3. | Look for broken, bent, pushed out or corroded terminals. |
| 4. | Perform any Technical Service Bulletins that may apply. |
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Replace the Glow Plug Module in accordance with the Service Information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).