P0490-EGR CONTROL CIRCUIT HIGH
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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 ignition on and the EGR Solenoid command on.
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Set Condition:
The Powertrain Control Module (PCM) detects a short to voltage on the EGR Valve Control circuits for 0.5 second.
Possible Causes |
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| (K683) EGR CONTROL (+) CIRCUIT SHORTED TO VOLTAGE |
| (K682) EGR CONTROL (-) CIRCUIT SHORTED TO VOLTAGE |
| 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 VOLTAGE
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| 1. | Turn the ignition off. |
| 2. | Disconnect the EGR Valve harness connector. |
| 3. | Disconnect the PCM C1 harness connector. |
| 4. | Remove the ASD Relay from the TIPM. |
| 5. | Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay Connector. |
| 6. | Turn the ignition on. |
| 7. | Measure the voltage of the (K683) EGR Control (+) circuit at the EGR Valve harness connector. |
Is there any voltage present?
Yes
- Repair the (K683) EGR Control (+) circuit for a short to voltage.
- 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 FOR THE (K682) EGR CONTROL (-) CIRCUIT SHORTED TO VOLTAGE
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| 1. | Measure the voltage of the (K682) EGR Control (-) circuit at the EGR Valve harness connector. |
Is there any voltage present?
Yes
- Repair the (K682) EGR Control (-) circuit for a short to voltage.
- 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. |
| 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
- Test complete.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Go To 5
5. POWERTRAIN CONTROL MODULE (PCM)
| 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. | Refer to 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 (PCM) in accordance with the service information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).