DTC 42 (EST/ECM Harness Wire Routing) Set

Number 83-T-46 Section 6 Date 07/83
Subject: TROUBLE CODE 42 - 1983 BONNEVILLE AND GRAND PRIX MODELS EQUIPPED WITH 3.8L V-6 ENGINE (ENGINE CODE A)
A condition of Trouble Code 42 being set on 1983 Bonneville or Grand Prix vehicles equipped with the 3.8L V-6 engine (VIN Code A) could be caused by the EST harness being routed too close to a spark plug wire. This may cause EST signals sent from the ECM to be interfered with by electro-magnetic fields created by a spark plug firing..



To correct this condition, route #2, #4 and #6 spark plug wires around the inside of the engine lift hook and the EST harness under and around the distributor (see illustration).. In addition, make sure the TPS and ISC harnesses are routed below the canister purge hose.