For 1990-2009 cars

# SES Light and Sever Engine Misfire On Cylinder 1 And 4 or Cylinders 2 And 3 - keywords ICM ignition miss module no P0300 P0301 P0302 P0303 P0304 plug repeat replacement spark

Subject: | SES Light and Severe Engine Misfire on Cylinders 1 and 4 or Cylinders 2 and 3

Models: | 2002-2005 Chevrolet Cavalier

| 2005-2006 Chevrolet Cobalt

| 2006-2006 Chevrolet HHR

| 2004-2006 Chevrolet Malibu

| 2004-2005 Chevrolet Malibu Classic

| 2002-2004 Oldsmobile Alero

| 2007 Pontiac G5

| 2002-2005 Pontiac Grand Am

| 2005-2006 Pontiac Pursuit (Canada Only)

| 2002-2005 Pontiac Sunfire

| 2003-2006 Saturn Ion

| 2004-2005 Saturn L Series

| 2002-2006 Saturn Vue

| with 2.2L Engine (VIN D or F - RPO L61)

This PI Supercedes To Remove 2007 Model Year. Please Discard PIP3433C

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

### Condition/Concern:

Some customers may comment on a severe engine misfire and a SES Light. Upon inspection, DTCs P0300 - P0304 may be found due to misfires on cylinders 1 and 4 or cylinders 2 and 3.

### Recommendation/Instructions:

If this concern is encountered, inspect circuits 406 (IC Control for 2/3 Coil) and 423 (IC Control for 1/4 Coil) for an intermittent short to ground or poor connection on either end. Depending on the model, these circuits may short on the AC lines near the AC compressor, on the transmission mount, or on the transmission lines where they enter the transmission. If there is no problem found with these circuits, inspect the ignition control module ground to ensure that it is clean and tight.

If there is no problem found after performing the suggestions above and the SI diagnostics lead to ignition module replacement, replace the ignition module as directed but also replace all of the spark plugs and clean the ignition module ground to possibly prevent future ignition module damage.

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.