ABS (DIAGNOSTICS) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC 42 POWER VOLTAGE MALFUNCTION

DTC DETECTING CONDITION:

Power supply voltage of the ABSCM&H/U is too low or too high.

TROUBLE SYMPTOM:

• ABS does not operate.

• EBD may not operate.

NOTE:

If EBD does not operate, the brake warning light illuminates in addition to ABS warning light. Both warning lights go off if voltage returns.

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK GENERATOR.

1) Start the engine.

2) Run the engine at idle after warming up.

3) Measure the voltage between generator terminal B and chassis ground.

Terminals

Generator B terminal (+) — Chassis ground (−):

Is the voltage 10 — 15 V?

Repair the generator.

2.CHECK BATTERY TERMINAL.

Turn the ignition switch to OFF.

Are the positive and negative battery terminals tightened securely?

Tighten the terminal.

3.CHECK INPUT VOLTAGE OF ABSCM&H/U.

1) Disconnect the ABSCM&H/U connectors.

2) Run the engine at idle.

3) Operate devices such as headlights, air conditioner, defogger, etc. which produce an electrical load.

4) Measure the voltage between ABSCM&H/U connector and chassis ground.

Connector & terminal

LHD model

(B301) No. 18 (+) — Chassis ground (−):

RHD model

(F49) No. 18 (+) — Chassis ground (−):

Is the voltage 10 — 15 V?

Repair the ABSCM&H/U power circuit.

4.CHECK THE ABSCM&H/U GROUND CIRCUIT.

1) Turn the ignition switch to OFF.

2) Measure the resistance between the ABSCM&H/U connector and chassis ground.

Connector & terminal

LHD model

(B301) No. 15 — Chassis ground:

RHD model

(F49) No. 15 — Chassis ground:

Is the resistance less than 0.5 Ω?

Repair the ABSCM&H/U ground harness.

5.CHECK POOR CONTACT IN CONNECTOR.

Is there poor contact in connector between generator, battery and ABSCM&H/U?

Repair the connector.

6.CHECK ABSCM&H/U.

1) Connect all connectors.

2) Erase the memory.

3) Perform the Inspection Mode.

4) Read the DTC.

Is the same DTC displayed?

Replace the ABSCM only.

7.CHECK ANY OTHER DTC ON DISPLAY.

Is there any other DTC displayed?

Check DTC using “List of Diagnostic Trouble Code (DTC)”.

Temporary poor contact occurs.