Fault code information
2 trip MIL
3 drive cycle recovery
Readiness group – None
Freeze frame type – Comprehensive
Description of component(s)
The EGR gas flow temperature is measured after the EGR cooler.
Effect on the system:
* Corrects EGR gas flow calculation (the temperature is an indication of the gas density)
* Closes the EGR valve when the EGR temperature is too high
* Monitors EGR cooler performance
Location of component(s)
Diagnostic condition
This diagnostic runs:
* when the ignition has been keyed off continuously for at least 8 hours;
* difference between the coolant and ambient temperature is less than 15°C [59°F];
* ambient temperature is more than -20°C [-4°F]
Set condition of fault code
The PCI ECU (D420) detects that the measured EGR temperature sensor differs by more than 3°C [37°F] from the average of other temperature sensor readings on/off the engine for more than 5 seconds (after the ignition has been keyed off for at least 8 hours).
Reset condition of fault code
The 8-hour ignition off diagnostics consists of three separate steps:
* The vehicle ignition may NOT be switched on or engine started for 8-10 consecutive hours (ideal situation would be overnight).
* Once the 8 to 10 consecutive hours have been reached, key on the ignition (NO engine start) and wait for 10 seconds to allow the system to power up and the diagnostics to run.
* Start the engine and let it idle for 2 minutes.
* This DTC changes to inactive when the fault is no longer detected.
Electrical diagram(s)
Technical data
Possible causes
EGR temperature sensor deviation
Additional information
For this diagnostic, the EGR temperature sensor (F749) reading is compared with an average of other temperature sensors on the engine after the ignition has been keyed off for at least 8 hours.
