Diagnosis & Repair
WARNING: This page is about a different car, the 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
- If using Lexus scan tool, go to next step. If not using Lexus scan tool, go to step 3.
- Connect Lexus scan tool to DLC No. 3. See Figure. Turn ignition on. Turn scan tool on. Using scan tool, read transaxle shift positions while shifting transaxle shift lever through all gear positions. If scan tool display does not indicate correct shifter positions, go to next step. If scan tool display indicates correct shifter positions, Park/Neutral Position (PNP) switch is functioning properly. Problem is internal transaxle. Identify symptom and repair as necessary. See appropriate article in AUTOMATIC TRANSMISSIONS.
- Access ECM behind glove box. Turn ignition on. Backprobing connector, measure voltage between ground and ECM E6 connector NSW circuit terminal No. 20 (Black/White wire). Also measure voltage between ground and ECM E7 connector "R" circuit terminal No. 8 (Red/Black wire), "2" circuit terminal No. 14 (Green/Yellow wire) and "L" circuit terminal No. 13 (Blue/Red wire). See Figure. Shift lever through all gear positions. See Fig 1. If voltage is not as specified, go to next step. If voltage is as specified, PNP switch is functioning properly.
- Check PNP switch. See ENGINE SENSORS & SWITCHES in appropriate SYSTEM & COMPONENT TESTING article. Replace PNP switch as necessary. If PNP switch is okay, check for open or short circuit in wiring harness between battery and PNP switch. Also check wiring harness between ECM and PNP switch. See WIRING DIAGRAMS article. Repair as necessary and retest system. If wiring harness is okay, replace ECM and retest system.