Inspection Procedure

Check ECU-IG fuse.

Fig 1: Locating ECU-IG Fuse
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

PREPARATION:

Remove the ECU-IG fuse from the cowl side J/B.

CHECK:

Check continuity of ECU-IG fuse.

OK: Continuity

NG: Check for short circuit in all the harness and components connected to ECU-IG fuse (For wiring diagrams, see ANTI-LOCK BRAKES ).

OK: Go to next step.
Check battery positive voltage.
OK: Voltage: 10 - 14 V

NG: Check and repair the charging system (See CHARGING SYSTEM ).

OK: Go to next step.
Check voltage of the ECU IG power source.
In case of using TOYOTA hand-held tester:

PREPARATION:
1. Connect the TOYOTA hand-held tester to the DLC3.
2. Turn the ignition switch ON and push the TOYOTA hand-held tester main switch ON.
3. Select the DATALIST mode on the TOYOTA hand-held tester.
CHECK:

Check the voltage condition output from the ECU displayed on the TOYOTA hand-held tester.

OK: "Normal" is displayed.

Fig 2: Checking Voltage
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

In case of not using TOYOTA hand-held tester:

PREPARATION:

Remove the ABS ECU with connectors still connected.

CHECK:
1. Turn the ignition switch ON.
2. Measure voltage between terminals IG1 and GND of ABS ECU connector.
OK: Voltage: 10 - 14 V

OK: Ignition switch OFF, check and replace ABS ECU.

NG: Go to next step.
Check for open circuit in harness and connector between ABS ECU and battery (See HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS ).
NG: Repair or replace harness or connector.

OK: Go to next step.
Check continuity between terminal GND of ABS ECU connector and body ground.
PREPARATION:

Disconnect the connector from the ABS ECU.

CHECK:

Measure resistance between terminal GND of ABS ECU harness side connector and body ground.

OK: Resistance: 1 Ω or less

Fig 3: Checking Ground Resistance
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Repair or replace harness or connector.

OK: Proceed to next circuit inspection show on problem symptoms table (See PROBLEM SYMPTOMS TABLE ).