Paccar

PACCAR MX (2004 Emissions) Fault Code: P1106 Engine Protection System – Power Derate Active

SET CONDITIONS:
This DTC becomes active if the DTC from which it originates has been active for a certain time.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC becomes inactive as soon as the DTC from which it originates has become inactive.

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?
– No, repair successful
– Yes, repair unsuccessful

ADDITIONAL INFORMATION:
IMPORTANT: Do not troubleshoot this DTC since it originates from another active DTC.

1. This DTC activates an engine torque derate.

2. This DTC is part of the engine protection system and can become active simultaneously with an active DTC related to:
– Low oil pressure
– High coolant temperature
– High oil temperature
– High intercooler temperature
– Low coolant level
– Low/high PCI ECU power supply
– High aftertreatment system temperatures

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

PACCAR MX (2004 Emissions) Fault Code: P1115 Engine Coolant Temperature – Data Valid but Too High, Moderately Severe

SET CONDITIONS:
The PCI ECU (D420) detects that measured coolant temperature is more than 110?C [230?F] for more than 10 s.

DIAGNOSTIC CONDITION:
This diagnosis runs continuously when the ignition is keyed ON.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to INACTIVE after the diagnosis runs and passes.

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?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Coolant level too low
2. Contaminated radiator
3. Blocked thermostat
4. Coolant temperature sensor deviation
5. Faulty engine cooling fan
6. Faulty engine coolant pump

ADDITIONAL INFORMATION:
1. The engine coolant temperature is monitored by the coolant temperature sensor (F566).
2. A yellow warning is active on the driver’s display.

PACCAR MX (2004 Emissions) Fault Code: P1122 Cruise Control Brake Signal – Data Erratic, Intermittent, or Incorrect

SET CONDITIONS:
The PCI ECU (D420) detects that both cruise control and engine torque are governed and at the same time the parking brake or foot brake pedal is applied.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the ignition is on.

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?
– No, repair successful
– Yes, repair unsuccessful

ADDITIONAL INFORMATION:
1. When cruise control is activated, the PCI ECU governs the engine torque to meet or maintain the cruise control target speed.
2. Cruise control can no longer be activated when this DTC is active.

PACCAR MX (2004 Emissions) Fault Code: P1128 Inlet Air Temperature In Inlet Manifold – Data Valid but Too High

SET CONDITIONS:
The PCI ECU (D420) detects that the inlet air temperature is above 125?C [257?F].

DIAGNOSTIC CONDITION:
The diagnostic starts to run 30 seconds after the engine is started.

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?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Contaminated intercooler
2. Faulty engine cooling fan
3. Boost temperature sensor deviation

ADDITIONAL INFORMATION:
1. The inlet air temperature is measured in the inlet manifold near cylinder 2 by the boost temperature sensor (F804).

2. When this DTC is active:
– The engine runs in protection mode
– DPF regeneration is disabled

PACCAR MX (2004 Emissions) Fault Code: P1133 Lambda Sensor Heater – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (C46)

SET CONDITIONS:
This DTC is set when the ECU detects a higher voltage than expected on the signal or control circuit of the ECU.

DIAGNOSTIC CONDITION:
The diagnostic runs continuously when the ignition is keyed on.

RESET CONDITION:
The DTC changes to inactive after the diagnostic runs and passes.

POSSIBLE CAUSES:
1. The sensor or actuator signal wiring has a short circuit to supply.
2. A malfunction of the sensor or actuator

PACCAR MX (2004 Emissions) Fault Code: P1134 Lambda Sensor Heater – Voltage Too Low or Short Circuit to Ground on ECU (D420) Pin (C46)

SET CONDITIONS:
This DTC is set when the ECU detects a lower voltage than expected on the signal or control circuit of the ECU.

DIAGNOSTIC CONDITION:
The diagnostic runs continuously when the ignition is keyed on.

RESET CONDITION:
The DTC changes to inactive after the diagnostic runs and passes.

POSSIBLE CAUSES:
1. The sensor or actuator signal wiring is interrupted.
2. The sensor or actuator signal wiring has a short circuit to ground.
3. A malfunction in the power supply of the sensor or actuator
4. A malfunction of the sensor or actuator

ADDITIONAL INFORMATION:
Multiple sensor related voltage-too-low DTCs can indicate a malfunction within a 5-V sensor power supply circuit of the PCI ECU.

PACCAR MX (2004 Emissions) Fault Code: P1135 Lambda Sensor Heater – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (C46)

SET CONDITIONS:
This DTC is set when the ECU detects a higher voltage than expected on the signal or control circuit of the ECU.

DIAGNOSTIC CONDITION:
The diagnostic runs continuously when the ignition is keyed on.

RESET CONDITION:
The DTC changes to inactive after the diagnostic runs and passes.

POSSIBLE CAUSES:
1. The sensor or actuator signal wiring has a short circuit to supply.
2. A malfunction of the sensor or actuator