PRE-RELEASE
DTC 42 POWER SUPPLY VOLTAGE TOO LOW
| DTC 42 POWER SUPPLY VOLTAGE TOO LOW |
DIAGNOSIS:
Power source voltage of the ABSCM&H/U is low.
TROUBLE SYMPTOM:
| • |
ABS does
not operate.
|
|
| • |
EBD does not operate.
|
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WIRING DIAGRAM:
CHECK GENERATOR.
Start the engine.Idle after warm-up.
Measure the voltage between generator B terminal and chassis ground.
Terminals
Generator B terminal (+) — Chassis ground (−):
Is the voltage 10 — 17 V?
| Yes |
| No |
Repair the generator.
CHECK BATTERY TERMINAL.
Turn the ignition switch to OFF.Are the positive and negative battery terminals tightly clamped?
| Yes |
| No |
Tighten the clamp of terminal.
CHECK INPUT VOLTAGE OF ABSCM&H/U.
Disconnect the connector from ABSCM& H/U.Run the engine at idle.
Operate the electric load applying devices, such as the headlight, A/C, and defogger.
Measure the voltage between ABSCM&H/U connector and chassis ground.
Connector & terminal
(B301) No. 18 (+) — Chassis ground (−):
Is the voltage 10 — 17 V?
| Yes |
| No |
Repair the harness connector between battery, ignition switch and ABSCM&H/U.
CHECK GROUND CIRCUIT OF ABSCM&H/U.
Turn the ignition switch to OFF.Measure the resistance between ABSCM&H/U connector and chassis ground.
Connector & terminal
(B301) No. 15 — Chassis ground:
Is the resistance less than 0.5 Ω?
| Yes |
| No |
Repair the ABSCM&H/U ground harness.
CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connectors between generator, battery and ABSCM&H/U?
| Yes |
Repair the connector.
| No |
CHECK ABSCM&H/U.
Connect all connectors.Erase the memory.
Perform the inspection mode.
Read out the DTC.
Is the same DTC as in the current diagnosis still being output?
| Yes |
Replace the ABSCM&H/U.
| No |
CHECK ANY OTHER DTC APPEARANCE.
Are other DTCs being output?
| Yes |
Proceed with the diagnosis corresponding to DTC.
| No |
A temporary poor contact.
