P0489-EGR CONTROL CIRCUIT LOW
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on and the EGR Solenoid command off.
- Set Condition:
The ECM detects a short to ground on the (K35) EGR Solenoid Control circuit for 0.48 seconds.
| Possible Causes |
| INTERMITTENT DTC |
| (K35) EGR SOLENOID CONTROL CIRCUIT SHORTED TO GROUND |
| (K35) EGR SOLENOID CONTROL CIRCUIT OPEN OR HIGH RESISTANCE |
| EGR VALVE |
| ENGINE CONTROL MODULE (ECM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Diagnostic Test
1. DTC IS ACTIVEIgnition on, engine not running.
With the scan tool, clear DTCs in the Engine Control Module (ECM).
With the scan tool, actuate the EGR Solenoid at 100%.
Monitor the scan tool for at least two minutes.
With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. (K35) EGR SOLENOID CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the Valve Block Assembly harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Measure the resistance between ground and the (K35) EGR Solenoid Control circuit in the Valve Block Assembly harness connector.
Is the resistance below 1000 ohms?
Yes
- Repair the (K35) EGR Solenoid Control circuit for a short to ground.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go to 3
3. (K35) EGR SOLENOID CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
Measure the resistance of the (K35) EGR Solenoid Control circuit between the Valve Block Assembly harness connector and the Engine Control Module (ECM) harness connector.
Is the resistance below 10.0 ohms?
Yes
- Go to 4
No
- Repair the (K35) EGR Solenoid Control circuit for an open circuit or high resistance.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
4. EGR VALVE
Connect the Engine Control Module (ECM) harness connector.
Turn the ignition on.
With the scan tool, actuate the Exhaust Gas Recirc Positioner to 100%.
Using a 12 volt test light connected to 12 volts, check the (K35) EGR Solenoid Control circuit in the Valve Block Assembly harness connector.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
NOTE: The circuit will remain actuated by the controller for 30 seconds. Be certain the actuation is active when checking the circuit.
With the scan tool, actuate the Exhaust Gas Recirc Positioner to 0%.
Using a 12 volt test light connected to 12 volts, check the (K35) EGR Solenoid Control circuit in the EGR Valve harness connector.
NOTE: The test light should not be illuminated.
NOTE: The circuit will remain actuated by the controller for 30 seconds. Be certain the actuation is active when checking the circuit.
Is the test light illuminated and bright with the actuation at 100% and not illuminated with the actuation at 0%?
Yes
- Replace the EGR Valve in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go to 5
5. ENGINE CONTROL MODULE (ECM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the EGR Valve and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Replace the Engine Control Module (ECM) in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)