DN90 - Check Intermittent Sensor

Continuous Memory Diagnostic Trouble Code (DTC) 328 or 327 indicates the EGR valve was closed further than normal or EGR Valve Position (EVP) sensor or circuit has failed with an intermittent low voltage sometime during vehicle operation. Continuous Memory DTC 337 indicates the EVP signal to the Powertrain Control Module (PCM) was above the maximum Self-Test limit sometime during vehicle operation.

Possible causes:

- Poor continuity in EVP harness or connectors.

- Intermittent open or short in EVP sensor or harness.

- Damaged EVP sensor.

- Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, reconnect PCM.

- Connect Digital Volt/Ohm Meter (DVOM) between test pin 27 and test pin 46 at the breakout box.

- Key "ON", engine "OFF".

- Lightly tap on EVP sensor and wiggle harness connector to simulate road shock.

NOTE: EVP voltage with EGR valve closed is normally between 0.24 and 0.67 volt and steady. A sudden change in voltage indicates a fault.

- Is a fault indicated?

Yes -- Remove and Inspect EVP sensor connector. If OK, replace EVP sensor. Clear continuous memory. Clearing Diagnostic Trouble Codes

Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Leave DVOM connected, reconnect PCM and go to DN91. DN91 - Check Vehicle Harness For Intermittent Opens or Shorts