Engine Control System Trouble Shooting - No Codes: Other Toyota 4Runner III

DOES NOT START

Engine Does Not Crank

1. Check battery and battery cables.
2. Check starter.
3. Check starter relay.

No Initial Combustion

1. Check ECM power source circuit with ignition on.
2. Check fuel pump control circuit.
3. Check for defective ECM, wiring or connections.
4. Check engine immobilizer system (if equipped).
5. Check for defective fuel pump switch (if equipped).

No Complete Combustion

1. Check fuel pump control circuit.

DIFFICULT TO START

Difficult To Start, Cranks Normal

1. Check starter signal circuit to STA circuit at ECM.
2. Check fuel pump control circuit.
3. Check engine compression.

Difficult To Start When Cold

1. Check starter signal circuit to STA circuit at ECM.
2. Check fuel pump control circuit.

Difficult To Start When Hot

1. Check starter signal circuit to STA circuit at ECM.
2. Check fuel pump control circuit.

POOR IDLING

High Idle Speed

1. Check A/C signal circuit.
2. Check ECM power source circuit with ignition on.

Low Idle Speed

1. Check A/C signal circuit.
2. Check fuel pump control circuit.

Rough Idle

1. Check engine compression.
2. Check fuel pump control circuit.

Surging

1. Check ECM power source circuit with ignition on.
2. Check fuel pump control circuit.

POOR DRIVEABILITY

Hesitation/Poor Acceleration

1. Check fuel pump control circuit.
2. Check for faulty automatic transaxle/transmission.
3. Check A/C cut control circuit (if equipped).

Surging

1. Check fuel pump control circuit.

ENGINE STALLS

Engine Stalls After Start

1. Check fuel pump control circuit.
2. Check engine immobilizer system (if equipped).

Engine Stalls During A/C Operation

1. Check A/C signal circuit.
2. Check for defective ECM, wiring or connections.

REFUELING PROBLEM

Note. This only applies to vehicles equipped with On-Board Refilling Vapor Recovery (ORVR) system.

Unable/Difficult To Refuel

1. Check ORVR system (if equipped).

Intermittent Simulation

To reproduce the conditions creating an intermittent fault, use the following methods

1. Lightly vibrate component. See «VIBRATION METHOD»(ref-91237-S11075969022001030600000) .
2. Heat component. See «HEATING METHOD»(ref-91237-S25148841582001030600000) .
3. Wiggle or bend wiring harness. See «VIBRATION METHOD»(ref-91237-S11075969022001030600000) .
4. Spray component with water. See «WATER SPRINKLING METHOD»(ref-91237-S09175410152001030600000) .

Monitor circuit/component voltage or resistance while simulating intermittent. If engine is running, monitor for Diagnostic Trouble Codes (DTCs). Use test results to identify a faulty component or circuit.

WATER SPRINKLING METHOD

Spray outside of vehicle and front of radiator with water while checking for a malfunction to occur. DO NOT spray water directly into engine compartment. Temperature and humidity may be changed by spraying water onto front of radiator. DO NOT spray electronic components directly with water.