DTC Advanced Diagnostics: P154B (1.5L Engine)
DTC P154B: Battery Sensor Characteristic Abnormal
General Description
The 12 volt battery sensor is connected between the 12 volt battery and ground. The 12 volt battery sensor measures the 12 volt battery's current, voltage, and temperature. The measured value is sent to the powertrain control module (PCM) via the LIN line by the request of the PCM. The 12 volt battery sensor detects a characteristic abnormal of the shunt resistor in the 12 volt battery sensor after the vehicle is turned to the OFF (LOCK) mode and the PCM judges as malfunction when the vehicle is turned to the ON mode. If the 12 volt battery sensor detects an abnormal of the current detection circuit during the measurement process of the 12 volt battery internal resistance by pulse discharge, the PCM detect a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Once per driving cycle |
| Sequence | Vehicle ON mode or 10 minutes after 12 volt battery sensor is activated |
| Duration | 10 seconds or more |
| DTC Type | Two drive cycles, MIL off |
Enable Conditions
| Condition | |
|---|---|
| Vehicle | ON mode |
Malfunction Threshold
The current detection circuit of the 12 volt battery sensor detects an abnormal for at least 10 seconds.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- 12 volt battery sensor internal failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, a Confirmed DTC, the freeze data, and the on-board snapshot are stored. The MIL does not come on.
Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.