A/T Interlock System - Key Interlock System Circuit Troubleshooting

  1. Measure the voltage between driver's under-dash fuse/relay box connector F (33P) terminal No. 4 and body ground.
Is there about 0 V while the shift lever is in P, and is there battery voltage when the shift lever is out of P?
YES -
Substitute a known-good driver's MICU and recheck. If the symptom goes away with a known-good driver's MICU, replace the original MICU. ■
NO -
Repair open or short to body ground in the wire between PCM connector terminal; R20A3 engine model: B13, K24Z3 engine model: B14, the transmission range switch, and the driver's MICU.■