VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC C0042 POWER SUPPLY VOLTAGE FAILURE

DTC DETECTING CONDITION:

Malfunction of VDCCM&H/U power supply voltage

TROUBLE SYMPTOM:

• ABS does not operate.

• EBD may not operate.

• VDC does not operate.

NOTE:

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 clamped tightly?

Tighten the terminal.

3.CHECK THE VDCCM&H/U INPUT VOLTAGE.

1) Disconnect the connector from the VDCCM&H/U.

2) Run the engine at idle.

3) Operate the devices such as headlights, air conditioner, defogger, etc. which produce much electrical loading.

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

Connector & terminal

(B310) No. 28 (+) — Chassis ground (−):

Is the voltage 10 — 15 V?

Repair the power supply circuit.

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

1) Turn the ignition switch to OFF.

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

Connector & terminal

(B310) No. 25 — Chassis ground:

Is the resistance less than 0.5 Ω?

Repair the VDCCM&H/U ground harness.

5.CHECK POOR CONTACT OF CONNECTORS.

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

Repair the connector.

6.CHECK THE VDCCM&H/U.

1) Connect all the connectors.

2) Clear the memory.

3) Perform the Inspection Mode.

4) Read the DTC.

Is the same DTC displayed?

Replace the VDCCM only.

7.CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diagnosis according to DTC.

Temporary poor contact occurs.