DTC Advanced Diagnostics: P1AF3 (1.5L Engine) (2025)
DTC P1AF3 : IG1 Voltage Correlation Abnormality
General Description
The powertrain control module (PCM) draws power for main CPU from +B_BACKUP_FI-ECU terminal, and draws power for activating the PCM from IG1 terminal. If the difference of system voltage between the PCM, the transmission control module (TCM), and the CAN gateway increases, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 10 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Engine speed [Engine Speed] | 550 rpm | - |
| 12 volt battery voltage [Battery]* 1 | - | 17.4325 V |
| 12 volt battery voltage [Battery]* 2 | - | 17.085 V |
| Vehicle | ON mode | |
*1: M/T
*2: CVT
[ ]: HDS Parameter
Malfunction Threshold* 1
The difference of system voltage between the PCM and the CAN gateway is 2 V or more for at least 10 seconds.
Malfunction Threshold* 2
The difference of system voltage between the PCM and the TCM is 2 V or more 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.
- 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, 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.