DTC Advanced Diagnostics: P26F2 (1.5L Engine) (2025)
DTC P26F2 : Starter Cut Relay Diagnosis Circuit Low Voltage
General Description
The starter control system prevents the starter from accidentally activating when the shift position is not in the P or N position/mode, or when the engine is running. If the vehicle is turned mistakenly while shift position is not in P or N or while the engine is running, the powertrain control module (PCM) will stop power to the starter cut relays. However, cranking to return from auto idle stop does not correspond to this. In this system, two starter cut relays are connected in series (starter cut relay 1 circuit, starter cut relay 2 circuit) to prevent the starter from running continuously due to a starter cut relay malfunction. Also a diagnosis line (ST_RLY_1_TO_2) is connected to monitor the voltage between the starter cut relay 1 circuit and starter cut relay 2 circuit. Based on the diagnosis line signals, the PCM detects an OPEN malfunction of diagnosis line, an ON malfunction of starter cut relay 1 circuit, and an ON malfunction of starter cut relay 2 circuit. The PCM also equips with return signal circuits of starter cut relay 1 circuit and starter cut relay 2 circuit to detect an OFF malfunction. If the voltage of the diagnosis line (ST_RLY_1_TO_2) is a specified voltage for a set time when the starter is OFF (STS OFF), the PCM detects an ON malfunction of starter cut relay 2 circuit and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 5 seconds or more |
| DTC Type | One drive cycle, MIL on* 1, off* 2 |
*1: USA/Canada models
*2: Mexico models
Enable Conditions
| Condition | Minimum |
|---|---|
| Vehicle | ON mode |
Malfunction Threshold
The diagnosis line (ST_RLY_1_TO_2) input voltage [Starter Cut Relay] is 2.2 V or less for at least 5 seconds.
[ ]: HDS Parameter
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.
- Starter cut relay 2 circuit ON failure
- Starter cut relay circuit ST_RLY_1_TO_2 line short to ground
- PCM internal circuit failure
Diagnosis Details* 1
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot are stored in the PCM memory.
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, a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot are stored in the PCM memory. 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.