Diagnosis & Repair
- If using OBD-II scan tool, go to next step. If using Lexus scan tool, connect scan tool to Data Link Connector (DLC) No. 3. See Figure. Turn ignition on. Turn scan tool on. Move shift lever through all gear positions one at a time. Read PNP, REVERSE, DRIVE, "4", "3", "2" and LOW signals on scan tool. If all signals switch from OFF to ON, replace ECM and retest. If all signals do not switch from OFF to ON, go to step 3.
- Access ECM behind glove box. Turn ignition on. Move shift lever through all gear positions one at a time. Backprobing, check for battery voltage between ground and appropriate ECM connector terminal at each gear position. See Figure. See IDENTIFYING ECM CONNECTORS & TERMINALS table. If battery voltage exists as specified, replace ECM and retest. If battery voltage does not exist as specified, go to next step.IDENTIFYING ECM CONNECTORS & TERMINALS
Gear Position ECM Connector Terminal No. (Wire Color) Park E11 15 (Green/White) Reverse (1) E11 2 (Red/Black) Neutral E11 20 (Green/Red) Drive E16 1 (Gray/Yellow) 4 E16 25 (Blue/Yellow) 3 E11 4 (Green) 2 E11 3 (Green/Black) Low E16 16 (Yellow/Black) (1) Voltage should be less due to back-up light illuminating. - Raise and support vehicle. Disconnect PNP switch Gray 10-pin connector. Move shift lever through all gear positions one at a time. Check for continuity between appropriate terminals at PNP switch Gray 10-pin connector at each gear position. See Fig 1. See IDENTIFYING PARK/NEUTRAL POSITION SWITCH TERMINALS table. If continuity does not exist as specified, replace PNP switch and retest. If continuity exists as specified, check for short or open circuit in wire harness and connector between battery and PNP switch, and PNP switch and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary.
IDENTIFYING PARK/NEUTRAL SWITCH TERMINALS
| Gear Position | Terminals No. |
|---|---|
| Park | 4-7 & 5-6 |
| Reverse | 4-8 |
| Neutral | 4-10 & 5-6 |
| Drive Or 4 | 4-9 |
| 3 | 2-4 |
| Low Or 2 | 3-4 |