PACCAR MX (2004 Emissions) Fault Code: P0115 Engine Coolant Temperature – Data Erratic, Intermittent or Incorrect During Overrun, at Ignition On

Description

PACCAR MX (2004 Emissions) Fault Code: P0115 Engine Coolant Temperature – Data Erratic, Intermittent or Incorrect During Overrun, at Ignition On

SET CONDITIONS:
The PCI ECU (D420) detects that the measured coolant temperature differs more than 3°C [5.4°F] from the average of other temperature sensors on the engine for more than 5 seconds (after the ignition has been keyed off for at least 8 hours).

DIAGNOSTIC CONDITION:
This diagnostic runs:
1. When the ignition has been keyed off continuously for at least 8 hours
2. Difference between the coolant and ambient temperature is less than 15°C [59°F]
3. Ambient temperature is more than -20°C [-4°F]

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Engine (block) heater used
2. Coolant temperature sensor deviation

ADDITIONAL INFORMATION:
For this diagnostic, the engine coolant temperature sensor (F566) reading is compared with average readings of other temperature sensors on/off the engine after the ignition has been keyed off for at least 8 hours.