Fuel Rail Temperature Sensor

Fuel Rail Temperature Sensor

Sensor Stuck
This monitor checks that the fuel rail temperature (FRT) sensor is not stuck at a particular value. If the engine has been off for greater than a calibrated time, then the next time the engine is started the diagnostic will run.

If the engine speed is over a calibrated limit, then the fuel rail temperature must change by a calibrated amount within a set time after engine start or a failure will be flagged. If the fuel rail temperature does change by equal to or greater than this threshold a normal judgement is made.

Range or Performance Failure
The monitor checks that the fuel rail temperature sensor is reading a correct value when compared to other sensors on the vehicle.

If the engine has been off for greater than a calibrated time period, then when the ignition is next switched on, the fuel rail temperature sensor reading is compared to the average of the sum of the ECT sensor and AAT sensor. The fuel rail temperature sensor must be within a calibrated threshold of this reading for a normal judgement to be made. If it is over this threshold, then a fault will be detected.

Range /Performance Flow Chart





Sensor Stuck Flow Chart








If the above table does not include details of the following enabling conditions: - IAT, ECT, vehicle speed range, and time after engine start-up then the state of these parameters has no influence upon the execution of the monitor.