DTC P0126, P0128 [LF]: Notes
DTC P0126, P0128 (LF) DETECTION CONDITION AND POSSIBLE CAUSE
DTC P0126
DTC P0128 |
Coolant thermostat stuck open |
| DETECTION CONDITION |
DTC P0126
- If the ECT sensor signal never exceeds 71°C {160°F}
after engine start for specified period, the PCM determines that the coolant thermostat is stuck open.
MONITORING CONDITIONS
- IAT: above -10°C {14°F}
- Vehicle speed: over 6 km/h {3.7 mph}
DTC P0128
- The PCM monitors MAR IAT, VSS and ECT signals and calculate radiator's heat radiation ratio while following monitoring conditions are met. If calculated value exceeds threshold, the PCM determines that the coolant thermostat is stuck open.
MONITORING CONDITIONS
- IAT: above -10°C {14°F}
- ECT at engine start: below 36°C {97°F}
- Difference between ECT at engine start and minimum IAT: below 6°C {10.8°F}
- Vehicle speed: over 30 km/h {18.6 mph}
Diagnostic support note
- This is an intermittent monitor (engine cooling system).
- The MIL illuminates if the PCM detects above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in PCM.
- PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
- FREEZE FRAME DATA (Mode 2/Mode 12) is available.
- The DTC is stored in the PCM memory.
|
| POSSIBLE CAUSE |
- Coolant thermostat malfunction
- ECT sensor malfunction
- PCM malfunction
|