P245D

P245D-EGR COOLER BYPASS CONTROL CIRCUIT HIGH




For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation

The Exhaust Gas Recirculation (EGR) Cooler Bypass Valve is used to redirect the EGR gases around the cooler when the engine is under certain operating conditions. The EGR Cooler Bypass Valve is a smart device which communicates it's status to the Powertrain Control Module (PCM). At key on the EGR Cooler Bypass Valve drives the signal line low and then high and the PCM monitors for the correct status response from the EGR Cooler Bypass Valve. Throughout engine operation the PCM sends commands via the signal circuit to the EGR Cooler Bypass Valve and monitors the status line to confirm that the EGR Cooler Bypass Valve has reached the commanded position. When a fault occurs, the EGR Cooler Bypass valve will send a signal of less than one Volt on the status line to the PCM. The PCM will light a MIL lamp after this monitor runs and fails in two consecutive drive cycles. The PCM will turn off the MIL lamp after the diagnostic passes in four consecutive drive cycles.

- When Monitored:
With the ignition on.

- Set Condition:
When the EGR Cooler Bypass Valve is commanded off by the Powertrain Control Module (PCM), and feedback is reading high on the signal circuit.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, record all Freeze frame data.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC return?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. Intermittent Condition Test

2. CHECK THE (K670) EGR COOLER BYPASS VALVE SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the EGR Cooler Bypass Valve harness connector.
3. Disconnect the PCM C1 harness connector.
4. Turn the ignition on.
5. Measure the voltage on the (K670) EGR Cooler Bypass Valve Signal circuit at the EGR Cooler Bypass Valve harness connector.

Is there any voltage present?

Yes

- Repair the (K670) EGR Cooler Bypass Valve Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK THE (K670) EGR COOLER BYPASS VALVE SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE




1. Turn the ignition off.
2. Measure the resistance at the (K670) EGR Cooler Bypass Valve Signal circuit between the EGR Cooler Bypass Valve harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the (K670) EGR Cooler Bypass Valve Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. POWERTRAIN CONTROL MODULE
1. Reconnect the PCM C1 harness connector.
2. Reconnect the EGR Cooler Bypass Valve harness connector.
3. Backprobe the (K670) EGR Bypass Signal circuit at the EGR Cooler Bypass Valve harness connector.
4. Connect a jumper between the (K670) EGR Bypass Signal circuit and ground.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did P245C become inactive?

Yes

- Replace the EGR Cooler Bypass Valve.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.