P245C

P245C-EGR COOLER BYPASS CONTROL CIRCUIT LOW




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 on by the Powertrain Control Module (PCM), and feedback is reading low on status line.





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 750 seconds.
5. Start the engine.
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 GROUND




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

Is the resistance below 10k Ohms?

Yes

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

No

- Go To 3

3. POWERTRAIN CONTROL MODULE




1. Reconnect the PCM C1 harness connector.
2. Turn the ignition on.
3. While monitoring a scan tool, connect a jumper between 12 Volts and the (K670) EGR Cooler Bypass Valve Signal circuit.

Did P245C become active?

Yes

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

No

- Replace and program the Powertrain Control Module. PCM/ECM Reprogramming