C4.4 and C6.6 Industrial Engines and Engines for Caterpillar Built Machines Caterpillar

The Electronic Control Module (ECM) detects one of the following conditions:

• The ECM has been powered for 3 seconds.

• Diagnostic code 0168-01 is not active.

• No 0262 codes are active for the analog sensors.

• No 0041 codes are active for the digital (PWM) sensors.

• Diagnostic codes 0774-03 and 0774-04 are not active.

• The frequency of the signal from the digital (PWM) sensor is less than 150 Hz for more than 1 second.

• The frequency of the signal from the digital (PWM) sensor is greater than 1050 Hz for more than 1 second.

System Response:

If equipped, the warning lamp will come on. The diagnostic code will be logged.

The engine will use the primary throttle until the fault is repaired.

If the primary throttle has a fault, the following conditions will occur:

• The engine will default to the limp home speed.

• If the engine speed is higher than the limp home speed, the engine will decelerate to the limp home speed.

• If the engine speed is lower than the limp home speed, the engine speed will remain at the current speed.

• The engine will remain at this speed while the diagnostic code remains active.

• All inputs from the faulty throttle are ignored by the ECM until the fault is repaired.

• All inputs from the repaired throttle will be ignored by the ECM until the keyswitch has been turned to the OFF position and then back to the ON position.

Monitor the configuration screen on the electronic service tool in order to determine the type of throttle position sensor that is used on the engine.

Test Step 1. Perform the following diagnostic procedure: Digital Throttle Position Sensor Circuit - Test

Results:

• OK - STOP