Paccar

PACCAR MX (2004 Emissions) Fault Code: P0666 Internal ECU Temperature – Data Erratic, Intermittent or Incorrect, at Ignition On SET CONDITIONS:The PCI ECU (D420) detects that the measured internal ECU 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 hours2. Difference between the coolant temperature and ambient temperature is less than 15?C [27?F]3. Ambient temperature is more than -20?C [-4?F]...

PACCAR MX (2004 Emissions) Fault Code: P0668 Internal ECU Temperature – Internal Error SET CONDITIONS:The temperature measured by the internal ECU temperature sensor is out of range low. 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 POSSIBLE CAUSES:Faulty temperature sensor, internally in ECU. Clear the fault with the diagnostic service tool....

PACCAR MX (2004 Emissions) Fault Code: P0669 Internal ECU Temperature – Internal Error SET CONDITIONS:The temperature measured by the internal ECU temperature sensor is out of range high. 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 POSSIBLE CAUSES:Faulty temperature sensor, internally in ECU. Clear the fault with the diagnostic service tool....

PACCAR MX (2004 Emissions) Fault Code: P0685 PCI ECU – Short Circuit to Ground on ECU (D420) Pin (B3) SET CONDITIONS:The PCI ECU (D420) detects a short circuit to ground on pin (B03). DIAGNOSTIC CONDITION:This diagnostic runs when the ignition is keyed on and off. CORRESPONDING OBD READINESS MONITOR:None RESET CONDITION:This DTC changes to inactive when the fault is no longer detected. REPAIR VERIFICATION:1. Clear all DTCs2. 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...

PACCAR MX (2004 Emissions) Fault Code: P0691 Electronically Controlled Fan – Voltage Too Low or Short Circuit to Ground on ECU (D420) Pin (C74) 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. CORRESPONDING OBD READINESS MONITOR:None RESET CONDITION:The DTC changes to inactive after the diagnostic 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...