Chart 6 Multiple PCM Codes

Circuit Description

Some powertrain components share common feeds and returns and certain failures of these circuits will cause multiple codes to set. The chart on the facing page lists the groups of codes set by the failure of common feeds and/or returns. If all of the codes in a group are set, perform the diagnosis listed in that box. If all of the codes in a group are not set, diagnose the lowest code number first.

Notes on Fault Tree

1. CKT 474 is the 5 volt feed from the PCM to the MAP sensor, TP sensor, EGR valve and BBV sensor. An open or short to ground in CKT 474 between the PCM's pin '3E16' and S235 will cause Codes P022, P032, P036 and P103 to set.
2. CKT 469 is the sensor return to the PCM from the IAT sensor and MAP sensor. An open in CKT 469 between S237 and S128 will cause Codes P031 and P038 to set.
3. CKT 469 is the sensor return to the PCM from the IAT sensor, MAP sensor, and transaxle temperature sensor. An open in CKT 469 between S237 and PCM's pin '2D1' will cause Codes P031, P038 and P059 to set.
4. CKT 476 is the sensor return to the PCM from the EGR valve, ECT sensor, BBV sensor and TP sensor. An open CKT 476 between S236 and PCM will cause Codes P015, P021, P036 and P102 to set.
5. CKT 750 is the battery feed from the engine compartment fuse block fuse 'D1' to the transaxle shift 'A/B' solenoids. An open in CKT 750 will cause Codes P029, P094, and P117 to set.
6. CKT 750 is the battery feed from the engine compartment fuse block fuse 'D1' to the TCC brake switch which feeds the torque converter clutch through CKT 420. An open in CKT 750 or CKT 420 or an open in the TCC contacts of the TCC brake switch will cause Codes P039 and P090 to set.
7. CKT 750 is the battery feed for the transaxle Shift 'A/B' solenoids, TCC brake switch and torque converter clutch. A short to ground on CKT 750, an open fuse 'D1' or an open feed to fuse 'D1' will cause Codes P029, P039, P090, P094 and P117 to set.