DTC Advanced Diagnostics: U0298 (1.5L Engine, PGM-FI System) (2025)
DTC U0298 : PGM-FI - DC-DC LIN Communication Error
General Description
The local interconnect network (LIN) line connects the DC-DC converter and the powertrain control module (PCM). The LIN uses a master/slave protocol to send and receive data to the different components on the line. The PCM is the master unit, which controls the engine electrical system. The 12 volt battery sensor, the alternator, and the DC-DC converter are the slaves. The DC-DC converter receives data from the PCM and provides feedback to the PCM, which allows the PCM to operate the engine electrical system efficiently. When the PCM does not receive signals from the DC-DC converter within its specified amount of time, 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 on* 1, off* 2 |
*1: USA/Canada models
*2: Mexico models
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Elapsed time after the vehicle condition is turned to the ON mode | 3 seconds | - |
| 12 volt battery voltage [Battery] | 10.0 V | - |
[ ]: HDS Parameter
Malfunction Threshold
Either one of the conditions is met for at least 5 seconds:
- The PCM cannot receive any information from the DC-DC converter via the LIN line.
- The information sent from the DC-DC converter is abnormal.
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 LIN(BATT_SENSOR) line open
- DC-DC converter LIN(BATT_SENSOR) line short
- 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.