PACCAR MX (2004 Emissions) Fault Code: P1110 Intercooler Efficiency – Too Low

PACCAR MX (2004 Emissions) Fault Code: P1110 Intercooler Efficiency – Too Low

SET CONDITIONS:
The PCI ECU (D420) detects that cooling capacity of the intercooler is too low for more than 40 seconds.

DIAGNOSTIC CONDITION:
This diagnostic runs:
1. 150 seconds after an engine start and
2. Engine is running at steady speed and load and
3. Coolant temperature is above 65?C [149?F] and
4. Vehicle speed is more than 25 km/h [15.5 mph] and

CORRESPONDING OBD READINESS MONITOR:
VTG monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Restricted air flow through intercooler/radiator.
2. Blocked intercooler
3. Fan not working correctly
4. Intercooler temperature sensor (F750) deviation
5. Ambient temperature sensor (OEM) deviation
6. Coolant temperature sensor (F566) deviation
7. EGR temperature sensor (F749) deviation
8. Pre-compressor air temperature (measured by humidity sensor (F852)) deviation
9. Inlet air temperature sensor (F804) deviation
10. Ambient air pressure sensor (internal PCI ECU sensor) deviation
11. Boost pressure sensor (F802) deviation

ADDITIONAL INFORMATION:
The temperature after the intercooler is measured by the intercooler temperature sensor (F750).

The cooling efficiency of the intercooler is monitored.

This diagnostics consists of two parts:
1. The temperature across the intercooler drop is monitored by comparing the calculated temperature before the intercooler with the measured temperature after the intercooler.

2. The measured temperature after the intercooler is compared with the ambient temperature.

Fault type:
1. Two drive cycle MIL on
2. Three drive cycle MIL recovery