DTC Advanced Diagnostics: P154B (3.5L Engine)
DTC P154B: Battery Sensor Characteristic Abnormal
General Description
Electrical management system consists of the 12 volt battery, the 12 volt battery sensor, the alternator, and the powertrain control module (PCM). The PCM monitors the battery charging level through the 12 volt battery sensor, and controls to optimum condition according to the driving condition to improve fuel economy and to secure recovering from the auto idle stop. The occurrence of the 12 volt battery sensor characteristic abnormal affects the electrical management. Therefore, if the PCM receives current abnormality detection flag from the 12 volt battery sensor, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 5 seconds or more |
| DTC Type | Two drive cycles, MIL off |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery] | 10.5 V | - |
| Vehicle | ON mode | |
[ ]: HDS Parameter
Malfunction Threshold
The PCM receives current abnormality detection flag from the 12 volt battery sensor for at least 5 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 failure
- PCM internal circuit 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 and the freeze data are stored. The MIL does not come on.
Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool clear command.