Pinpoint Test B: DTC C1288 - Pressure Transducer Main/Primary Input Circuit Failure

WARNING: This page is about a different car, the 2004 Mercury Monterey and 2004 Ford Freestar. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Use the flex probe kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.

B1 CHECK THE SPEED CONTROL
- Operate the speed control.
- Does the speed control operate correctly?
Yes

GO to B2.

No

For further diagnosis of the speed control, REFER to SPEED CONTROL .
B2 CHECK FOR VOLTAGE TO THE ABS MODULE
- Key in OFF position.
- Disconnect: ABS Module C155.
- Key in ON position.
- Measure the voltage between the ABS module C155-6, circuit 535 (LB/RD), harness side and ground.
  
  Fig 1: Checking ABS Module Voltage
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes

GO to B3.

No

REPAIR the circuit. CLEAR the DTCs. TEST DRIVE the vehicle. REPEAT the self-test.
B3 MONITOR THE ABS MODULE BRAKE PRESSURE TRANSDUCER PID
- Enter the following diagnostic mode on the diagnostic tool: ABS Module Brake Pressure Transducer PID.
- Press and release the brake pedal while monitoring the brake pressure transducer PID.
- Does the PID increase with increased brake pedal pressure and decrease with decreased brake pedal pressure?
Yes

INSTALL a new ABS module. REFER to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE . CLEAR the DTC. REPEAT the self-test.

No

INSTALL a new HCU. REFER to HYDRAULIC CONTROL UNIT (HCU) . CLEAR all DTCs. REPEAT the self-test.