Fix code P0742 Check engine light on – GM
GM has issued a service bulletin 06-07-30-034 to address a P0742 check engine light on or a P2764 or P2761 codes on the vehicles listed below.
2006-2007 Buick Allure (Canada), LaCrosse, Lucerne, Rendezvous, Terraza
2006-2007 Chevrolet Impala, Malibu SS, Malibu Maxx SS, Monte Carlo, Uplander
2006-2007 Pontiac Grand Prix, G6, GTP, Montana SV6;
2006-2007 Saturn Relay; with 4T65-E Automatic Transmission (RPOs MN7, M15 or M76)
GM has determined that the tan wire to the torque converter clutch solenoid valve may be routed around a metal clip cause the wire to chafe and short to ground. That can cause all the trouble codes as well as harsh shifting due to high line pressure. If you find a chafe on this wire, do not attempt to splice it. Replace it with an updated harness. Make sure you route the new harness outside of the metal clip.