## DTC Troubleshooting: P0406 (12-5)

DTC P0406 (12-5): | EGR Valve Position Sensor Circuit High Voltage

1. | Reset the ECM/PCM.

2. | Start the engine. Is DTC P0406 indicated? YES - Go to 3. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the EGR valve and at the ECM/PCM.n

3. | Turn the ignition switch OFF.

4. | Disconnect the EGR valve 6P connector.

5. | Turn the ignition switch ON (II).

6. | Measure voltage between the EGR valve 6P connector terminals No. 2 and No. 3. Is there about 5 V? YES - Replace the EGR valve.n NO - Go to 7.

7. | Measure voltage between ECM/PCM connector terminals A10 and A20. Is there about 5 V? YES - Repair open in the wire between the EGR valve and the ECM/PCM (A10).n NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/ PCM.n