P0489-EGR CONTROL CIRCUIT LOW
P0489-EGR CONTROL CIRCUIT LOW
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For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Exhaust Gas Recirculation (EGR) Valve is opened by a motor located inside the EGR Valve. The pulse width modulated motor is controlled by the Powertrain Control Module (PCM). The EGR Valve also has an internal three wire 5-Volt EGR Position Sensor. This internal sensor reports the position of the valve back to the PCM over the EGR Position Sensor Signal circuit. The EGR system and Diesel Particulate Filter regeneration is disabled when the fault is active.
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When Monitored:
With the engine running.
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Set Condition:
The Powertrain Control Module (PCM) detects a short to ground on the EGR Valve Control circuits for 0.5 seconds.
Possible Causes |
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| (K683) EGR CONTROL (+) CIRCUIT SHORTED TO GROUND |
| (K682) EGR CONTROL (-) CIRCUIT SHORTED TO GROUND |
| EGR VALVE |
| POWERTRAIN CONTROL MODULE (PCM) |
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. | Start the engine and test drive the vehicle until the engine reaches operating temperature. |
| 4. | With the scan tool, select View DTCs. |
Is the status Active for this DTC?
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 (K683) EGR CONTROL (+) CIRCUIT FOR A SHORT TO GROUND
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| 1. | Turn the ignition off. |
| 2. | Disconnect the EGR Solenoid harness connector. |
| 3. | Disconnect the PCM C1 harness connector. |
| 4. | Measure the resistance between ground and the (K683) EGR Control (+) circuit at the EGR Valve harness connector. |
Is the resistance below 10k Ohms?
Yes
- Repair the (K683) EGR Control (+) circuit for a short to ground.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
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Go To 3
3. CHECK THE (K682) EGR CONTROL (-) CIRCUIT FOR A SHORT TO GROUND
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| 1. | Measure the resistance between ground and the (K682) EGR Control (-) circuit at the EGR Valve harness connector. |
Is the resistance below 10k Ohms?
Yes
- Repair the (K682) EGR Control (-) circuit for a short to ground.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
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Go To 4
| 1. | Replace the EGR Valve in accordance with the service information. |
| 2. | Turn the ignition on. |
| 3. | With the scan tool, erase DTCs in the PCM. |
| 4. | Start the engine and test drive the vehicle until the engine reaches operating temperature. |
| 5. | With the scan tool, select View DTCs. |
Did the DTC return?
Yes
- Go To 5
No
- Test complete.
- 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 EGR Valve and the Powertrain Control Module (PCM). |
| 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 Powertrain Control Module in accordance with the service information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).