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| Illustration 1 | g01448445 |
Schematic of the Left Brake Pedal Position Sensor | |
This diagnostic code is recorded when the ECM reads the signal voltage of the left brake pedal position sensor and the voltage is too low.
The operating range for the output voltage of the sensor is below normal.
The output frequency of the position sensor is approximately 500 hertz. The value of the sensor's duty cycle is approximately 50% in the depressed position. The duty cycle of the signal increases as the brake pedal is pressed. The value of the sensor's duty cycle is approximately 85% in the pressed position. The duty cycle of the signal decreases as the brake pedal is moved from the PRESSED position to the DEPRESSED position. The value of the sensor's duty cycle is approximately 15% in the depressed position.
The possible causes of this diagnostic code are listed here:
- The sender has failed.
- The signal circuit in the machine harness is shorted to ground.
- The ECM has failed. This is unlikely.
Test Step 1. CHECK THE SENSOR.
- Disconnect the machine harness from the sender.
Expected Result:
The diagnostic code changes from CID 0737 FMI 04 to CID 0737 FMI 03.
Results:
- OK - The diagnostic code changed from CID 0737 FMI 04 to CID 0737 FMI 03. This indicates that the failure is no longer present. The sender has failed.
Repair: Replace the sender.
STOP
- NOT OK - The diagnostic code remains. The failure remains present. The sender is not causing the failure. Proceed to test step 2.
Test Step 2. CHECK THE HARNESS.
- The sender remains disconnected from the machine harness.
- Turn the disconnect switch and the key start switch to the OFF position.
- Disconnect the machine harness connectors from the ECM.
- At the machine harness connector for the sender, measure the resistance between the signal contact 3 (wire G746-WH) and frame ground.
Expected Result:
The resistance is greater than 5000 ohms.
Results:
- OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. The ECM may have failed.
Repair: It is unlikely that the ECM has failed. Exit this procedure, and perform this procedure again. If the failure is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP
- NOT OK - The resistance is less than 5000 ohms. The machine harness has failed. There is a short between frame ground and the signal circuit in the machine harness.
Repair: Repair the machine harness or replace the machine harness.
STOP