Diagnosis & Repair (Using Hand-Held Tester)
WARNING: This page is about a different car, the 2003 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
- Start engine. Read throttle motor current value on the hand-held tester. At idle, if 7 amps or less is present, go to next step. If motor current value is above 7 amps, disconnect the throttle motor connector. At idle, if 7 amps or more are present, go to step 3. With throttle motor connector disconnected, if 7 amps or less is present, go to next step.
- Disconnect the throttle control motor connector. Measure the resistance between the terminals of throttle control motor terminals No. 1 and 2. See Figure. Resistance should be .3-100 ohms at 68°F (20°C). If resistance is to specification, go to next step. If resistance is not to specification, replace throttle body assembly.
- Disconnect the T2 throttle control motor 2-pin connector. See Figure. Disconnect the E2 ECM connector. See Figure. Check the continuity between the wire harness side connectors. See THROTTLE CONTROL MOTOR/ECM CONTINUITY CHECK table. If continuity is to specification, go to next step. If continuity is not to specification, repair or replace harness and connector as necessary.
- Turn the ignition switch ON. Read the throttle motor current value on the hand-held tester. At idle, current should be 7 amps or less. With accelerator pedal quickly released, current should be .5 amps or more. If okay, check for intermittent problems. If not okay, replace ECM.
THROTTLE CONTROL MOTOR/ECM CONTINUITY CHECK
| Terminals No. | Specification |
|---|---|
| -(T2-2) - M+ (E2-3) | Continuity |
| -(T2-1) - M- (E2-2) | Continuity |
| -(T2-2) Or M+ (E2-3) - E1 (E3-7) | No Continuity |
| -(T2-1) Or M- (E2-2) - E1 (E3-7) | No Continuity |