Models affected: 2006 and prior General Motors cars and light-duty trucks, 2003-’06 HUMMER H2, 2006 HUMMER H3 and 2005-’06 Saab 9-7X.

When servicing a vehicle for any type of customer concern — such as miscellaneous DTCs, intermittent driveability concerns, hard start, no start, incorrect gauges, inoperative air conditioning systems, service engine soon lamps illuminated, 4WD lamp illuminated, instrument panel gauges inoperative or cruise inoperative — the following steps are imperative. Inspect and ensure the integrity of all related wiring harness connectors. If the wiring harness connectors are not properly put together or engaged before they are locked together, numerous types of intermittent conditions may occur, which may include any of the symptoms listed above and possibly others.

The first step in any type of electrical diagnosis is a visual and physical inspection of the wiring harness connectors for integrity. Many times, the vehicle may be repaired just by disconnecting and reconnecting the connectors. As with all re...