Engine Does Not Crank
- Check starter.
- Check starter relay.
No Initial Combustion
- Check ECM power source circuit (ignition keyed).
- Check fuel pump control circuit.
No Complete Combustion
- Check fuel pump control circuit.
Difficult To Start Normally
- Check starter signal circuit. See CODE P1500 in appropriate articles
For ES300 TESTS W/CODES - OBD-II
For LS400 TESTS W/CODES - OBD-II
- Check fuel pump control circuit.
- Check engine compression.
Difficult To Start When Cold
- Check starter signal circuit. See CODE P1500 in appropriate articles
For ES300 TESTS W/CODES - OBD-II
For LS400 TESTS W/CODES - OBD-II
- Check fuel pump control circuit.
Difficult To Start When Hot
- Check starter signal circuit. See CODE P1500 in appropriate article
For ES300 TESTS W/CODES - OBD-II
For LS400 TESTS W/CODES - OBD-II
- Check fuel pressure control VSV circuit.
- Check fuel pump control circuit.
High Idle Speed
- Check A/C signal circuit.
- Check ECM power source circuit (ignition keyed).
Low Idle Speed
- Check A/C signal circuit.
- Check fuel pump control circuit.
Rough Idle
- Check engine compression.
- Check fuel pump control circuit.
Surging
- Check ECM power source circuit (ignition keyed).
- Check fuel pump control circuit.
Hesitation/Poor Acceleration
- Check fuel pump control circuit.
- Check for faulty automatic transmission (electronics).
- Check fuel pump control circuit.
Engine Stall After Start
- Check fuel pump control circuit.
Intermittent Simulation
Monitor circuit/component voltage or resistance while using the following procedures to simulate an intermittent fault. If engine is running, check for self-diagnostic codes. Use test results to identify a faulty component or circuit.
- Lightly vibrate component.
- Heat component.
- Wiggle or bend wiring harness.
- Spray component with water mist.
- Remove vacuum from component.
- Apply vacuum to component.