Paccar

PACCAR MX (2004 Emissions) Fault Code: P1223 Injector Solenoid Valve Cylinder 4 – Voltage Too Low or Short Circuit to Ground on ECU (D420) Pin (A12)

SET CONDITIONS:
The PCI ECU (D420) detects a too low voltage or a short circuit to ground on the ECU pin A12 circuit.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected. To enable the injector output, the DTC must be cleared.

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. Short circuit to ground in the circuit of ECU pin:
– A12 or
– A4 or
– A8
2. Faulty injector 4 or 5 or 6

ADDITIONAL INFORMATION:
The injector output is disabled by the PCI ECU when this DTC is detected. The output stays disabled until the DTC is cleared.

PACCAR MX (2004 Emissions) Fault Code: P1226 Injector Solenoid Valve Cylinder 1, 2, 3 – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (A2) or Pin (A10) or Pin (A6)

SET CONDITIONS:
The PCI ECU (D420) detects a too high voltage or a short circuit to supply on the ECU pin A2 or A6 or A10 circuit.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected. To enable the injector output, the DTC must be cleared.

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:
Short circuit to supply in the circuit of ECU pin:
A2 or; A6 or; A10

ADDITIONAL INFORMATION:
The injector output is disabled by the PCI ECU when this DTC is detected. The output stays disabled until the DTC is cleared.

PACCAR MX (2004 Emissions) Fault Code: P1227 Injector Solenoid Valve Cylinder 4, 5, or 6 – Voltage Too Low or Short Circuit to Ground on ECU (D420) Pin (A11) or Pin (A3) or Pin (A7)

SET CONDITIONS:
The PCI ECU (D420) detects a too low voltage or a short circuit to ground on the ECU pin A3 or A7 or A11 circuit.

DIAGNOSTIC CONDITION:
This diagnostic runs when the engine is running.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected. To enable the injector output, the DTC must be cleared.

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:
Short circuit to ground in the circuit of ECU pin:
A3 or; A7 or; A11

ADDITIONAL INFORMATION:
The injector output is disabled by the PCI ECU when this DTC is detected. The output stays disabled until the DTC is cleared.

PACCAR MX (2004 Emissions) Fault Code: P1230 Common Rail Pump Unit 1 – Short Circuit Between ECU (D420) Pin (A25) and Pin (A26)

SET CONDITIONS:
The PCI ECU (D420) detects a short circuit between ECU pin A25 and pin A26.

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

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive after the ignition has been switched off for at least 15 seconds and switched on again and 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:
Malfunctioning of the common rail pump unit 1 (L092) or wiring

ADDITIONAL INFORMATION:
When this DTC is active:
1. The engine torque is reduced.
2. The engine runs in protection mode.
3. The maximum rail pressure is limited to 1300 bar.

PACCAR MX (2004 Emissions) Fault Code: P1234 Common Rail Pump Unit 2 – Short Circuit Between ECU (D420) Pin (A27) and Pin (A28)

SET CONDITIONS:
The PCI ECU (D420) detects a short circuit between ECU pin A27 and pin A28.

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

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive after the ignition has been switched off for at least 15 seconds and switched on again and 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:
Malfunctioning of the common rail pump unit 2 (L093) or wiring

ADDITIONAL INFORMATION:
When this DTC is active:
1. The engine torque is reduced.
2. The engine runs in protection mode.
3. The maximum rail pressure is limited to 1300 bar.