DTC P0A94 (1.5 L Engine) (2020 2021)
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 12 volt battery voltage lowering when recovering (starter motor running) from idle stop condition. The DC-DC converter is connected with DCDC STS line which the powertrain control module (PCM) sends a voltage boost request and the local interconnect network (LIN) line which the DC-DC converter sends a diagnostic results 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 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 a DC-DC converter failure information via the LIN line for at least 5 seconds.
Possible Cause
NOTE: 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/DC2 line open
- DC-DC converter IG1 ACG line open
- DC-DC converter GND line open
- DC-DC converter +B DC/DC1 line short
- DC-DC converter +B DC/DC2 line short
- DC-DC converter DCDC STS line short
- DC-DC converter DCDC OUT1 line short
- DC-DC converter DCDC OUT2 line short
- Electrical unit failure
- DC-DC converter 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 or by disconnecting the 12 volt battery.