HE92 - Inspect EGR Vacuum Signal For Intermittent Failure

- Key Off.

- Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box and connect PCM to breakout box.

- Disconnect hose at EGR valve and connect to a vacuum gauge.

- Key On, Engine Running.

- Jumper Test Pin 47 (EVR) to chassis ground to activate the EVR to full ON. At idle, the vacuum gauge should read above 4.0 inHg.

- Observe vacuum gauge for an indication of a fault while performing the following:
- Lightly tap on the EVR solenoid and wiggle the EVR solenoid connector, vacuum lines and vehicle harness between the solenoid and PCM. A fault is indicated by a sudden drop in vacuum reading.

- Is a fault indicated?

YES -- ISOLATE fault and SERVICE as necessary. RECONNECT all components. Complete PCM reset to clear DTCs. Clearing Diagnostic Trouble Codes

Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes

NO -- Unable to duplicate and/or identify fault at this time. (In cold climates, the EGR valve may temporarily freeze shut and thaw when the engine warms up causing the intermittent DTC.) GO to Pinpoint Test Step Z1 with the following data: DPFE, EVR and VREF PIDs and list of Possible Causes. Z1 - Intermittent Test Procedure