DTC Advanced Diagnostics: P0A11 (1.5L Engine) (2025)
DTC P0A11 : DC-DC Converter Activation Circuit Malfunction
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 PCM requests DC-DC converter to boost up the voltage via the DC_STS line, the boost voltage circuit in the DC-DC converter boosts the 12 volt battery voltage and provides to other electrical units. Also, the DC-DC converter sends a DC_STS signal receipt notification to the PCM via the LIN line. If the PCM does not receive a DC_STS signal receipt notification from the DC-DC converter via the LIN for a set time after the PCM sent a voltage boost request via the DC_STS line, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Recovered from auto idle stop condition |
| Sequence | None |
| Duration | 5 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 | |
| Other | DC_STS ON or within 5 seconds after DC_STS OFF | |
[ ]: HDS Parameter
Malfunction Threshold
The PCM does not receive a DC_STS signal receipt notification from the DC-DC converter via the LIN 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.
- DC-DC converter DC_STS line open
- 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.