Diagnosis & Repair
WARNING: This page is about a different car, the 2002 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Lexus scan tool can be used to confirm PNP switch signal from CURRENT DATA.
- Access ECM behind glove box. Turn ignition on. Using DVOM, backprobe ECM harness connector and measure voltage between ground and specified terminal at ECM harness connector E9 (unless specified otherwise) with shift lever in appropriate position. See PARK/NEUTRAL POSITION SWITCH VOLTAGE table. See Figure. If voltage is as specified, replace ECM. If voltage is not as specified, go to next step.PARK/NEUTRAL POSITION SWITCH VOLTAGE
Shift Lever Position Terminal No. Volts Park & Neutral 2 (1); 1, 2, 3 & 8 Zero Reverse 2 (1) (2) 9-14.0 3 (2) 7.5-14.0 1, 2 & 8 Zero Drive 2 (1) 9-14 8 7.5-14.0 1, 2 & 3 Zero 2 2 (1) 9-14 2 7.5-14.0 1, 3 & 8 Zero Low 2 (1) 9-14 1 7.5-14.0 2, 3 & 8 Zero (1) Test at ECM connector E10. (2) Voltage may be slightly less due to lighting of reverse lights. - Disconnect PNP switch Gray 9-pin harness connector. Check continuity between appropriate PNP switch terminals (component side) with shift lever in appropriate position. See IDENTIFYING PARK/NEUTRAL POSITION SWITCH CONTINUITY table. See Fig 1. If problem exists, replace PNP switch. If problem does not exist, go to next step.IDENTIFYING PARK/NEUTRAL SWITCH CONTINUITY
Gear Position Terminals No. Park 1-3 & 6-9 Reverse 2-3 Neutral 3-5 & 6-9 Drive 3-7 2 3-4 Low 3-8 - Check wiring between battery and PNP switch and between PNP switch and ECM. See WIRING DIAGRAMS article. Repair wiring as necessary.