DTC 142

DTC P0A1D/142 HYBRID POWERTRAIN CONTROL MODULE

CIRCUIT DESCRIPTION

DTC Detection Condition:

When the ST turned ON at the ignition switch on the previous model, the ignition switch transmitted the ST signal to the HV control ECU. The new Prius has adopted a push button start system. When the driver pushes on the power switch while depressing the brake pedal, the power source control ECU transmits the ST signal to the HV control ECU. The HV control ECU monitors the ST signal to detect malfunction. If the ST signal is shorted to the +B power supply, the ST will be constantly ON, which will cause the HV system to start by merely turning the power switch ON (IG). The HV control ECU monitors the ST signal to prevent this from occurring.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Component Operating Range:

The HV control ECU monitors an ST signal input from the power source control ECU. If the ST signal is shorted to the +B power supply, the HV control ECU interprets this as the ST signal error, and then illuminates the MIL and sets a DTC.

Wiring Diagram:

Step 1:

Step 2:

INSPECTION PROCEDURE