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C109F Ford Code - Vacuum Sensor Signal Fault

- Code Popularity: 5,529 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC C109F Ford?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Loose Brake Booster Vacuum Hose
  • Faulty Brake Booster Vacuum Sensor
  • Brake Booster Vacuum Sensor harness is open or shorted
  • Brake Booster Vacuum Sensor circuit poor electrical connection
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How to Fix the DTC C109F Ford?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C109F Ford code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Anti-Lock Brake System (ABS) Warning Light ON
  • Engine Light ON (or Service Engine Soon Warning Light)

Code C109F Ford Description

The vacuum sensor is used by the Anti-Lock Brake System (ABS) Module to determine if hydraulic pump intervention is necessary due to loss of vacuum in the booster. The ABS module sends a 5-volt reference voltage to the sensor, the sensor compares the pressure in the booster to the ambient air pressure in the engine compartment and sends a varying voltage back to the ABS module based on the difference between the pressures. Normally, the pressure in the booster is much lower than ambient air pressure. As the pressure in the booster gets higher (closer to matching ambient air pressure), the lower the voltage sent back to the ABS module becomes.
When the vacuum in the brake booster falls below a predetermined level, the ABS module will command the hydraulic pump motor to activate on the next (and any subsequent) brake pedal application to assist with vehicle braking. The ABS module will continue to use the pump motor for braking assist as long as the low vacuum condition exists.

OBDII Code C109F Ford - Vacuum Sensor Signal Fault - AutoCodes.com
C109F Ford Code - Vacuum Sensor Signal Fault

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Code C109F Ford comments

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