DTC Advanced Diagnostics: P0A94 (1.5L Engine) (2025)
DTC P0A94 : DC-DC Converter Performance Problem
General Description
The auto idle stop system equipped vehicle uses the DC-DC converter to prevent electronic accessory reset due to the 12 volt battery voltage lowering when recovering (starter motor running) from auto idle stop condition. The DC-DC converter is connected with DC_STS line for the powertrain control module (PCM) to send a voltage boost request and the local interconnect network (LIN) line for sending a diagnostic result to the PCM. When the self-diagnostic circuit in the DC-DC converter detects a failure, it is noticed to the PCM via the LIN line. If the PCM receives a DC-DC converter failure information for a set time, the PCM detects a DC-DC converter performance problem and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 5.0 seconds or more |
| DTC Type | Two drive cycles, MIL on* 1, off* 2 |
*1: USA/Canada models
*2: Mexico models
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery] | 10.5 V | - |
| Vehicle | ON mode | |
[ ]: HDS Parameter
Malfunction Threshold
The PCM receives a DC-DC converter failure information via the LIN line for at least 5.0 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.
- DC-DC converter +B_DC/DC1 line open
- DC-DC converter +B_DC/DC1 line short
- DC-DC converter +B_DC/DC2 line open
- DC-DC converter +B_DC/DC2 line short
- DC-DC converter DC_STS line short
- DC-DC converter IG1 ST CUT RLY line open
- DC-DC converter DCDC_OUT1 line short
- DC-DC converter DCDC_OUT2 line short
- DC-DC converter GND line open
- Electrical unit failure
- DC-DC converter failure
- PCM internal circuit failure
Diagnosis Details* 1
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, the MIL comes on and a Confirmed DTC, the freeze data, and the on-board snapshot are stored.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.
Diagnosis Details* 2
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.