For 1990-2009 cars

# Noise From The Rear Of Vehicle - keywords canister cold CVS click evap knock L61 LE5 solenoid tick vent

Subject: | Noise From Rear of Vehicle

Models: | 2006-2007 Saturn ION

| 2006-2008 Chevrolet Cobalt

| 2007-2008 Pontiac G5

| 2006-2008 Chevrolet HHR

| 2005-2008 Pontiac Pursuit

| with Engine RPO L61 or LE5

This PI was superseded to update models and model years. Please discard PIC4317B.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

### Condition/Concern:

A noise may be heard from the rear of vehicle; typically 3-5 knocks during initial cold start. The noise may sound like someone outside of the vehicle is tapping on the back window or on the rear exterior body panels.

### Recommendation/Instructions:

This noise is from the vehicle's EVAP canister vent solenoid going through the diagnostic cleaning cycle, which is part of the software calibration set-up. Replacing the EVAP canister may not resolve the issue when the vehicle is re-exposed to a cold start. No parts should be replaced. This should be considered a normal condition for 2008 and previous model years.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.