Brake System - General Information: Overview Mercury Sable V

Normal Operation

The adjustable pedal switch receives fused battery voltage from smart junction box (SJB) fuse 27 (20A) along circuit SBP27 (BU/RD).

When the adjustable pedal switch is placed in the forward position, voltage is sent to the adjustable pedal motor along circuit CPP09 (VT/OG), passes through the motor and returns to the switch along circuit CPP10 (BN/BU) where it is grounded along circuit GD111 (BK/BU). This causes the pedal to move forward (away from the driver).

When the adjustable pedal switch is placed in the forward position, voltage is sent to the adjustable pedal motor along circuit CPP10 (BN/BU), passes through the motor and returns to the switch along circuit CPP09 (VT/OG) where it is grounded along circuit GD111 (BK/BU). This causes the pedal to move rearward (toward the driver).

This pinpoint test is intended to diagnose the following

1. Foreign material
2. Fuse
3. Wiring, terminals or connectors
4. Adjustable pedal cable
5. Adjustable pedal switch
6. Adjustable pedal motor

The adjustable pedal switch receives fused battery voltage from smart junction box (SJB) fuse 27 (20A) along circuit SBP27 (BN/RD).

When the adjustable pedal switch is placed in the forward position, voltage is sent to the driver seat module (DSM) along circuit CPP09 (VT/OG), the DSM then sends the voltage to the adjustable pedal motor along circuit CPP09 (VT/OG), the voltage passes through the motor and returns to the DSM along circuit CPP10 (BN/BU). The DSM then sends the voltage back to the switch along circuit CPP10 (BN/BU) where it is grounded along circuit GD111 (BK/BU). This causes the pedal to move forward (away from the driver).

When the adjustable pedal switch is placed in the forward position, voltage is sent to the DSM along circuit CPP10 (BN/BU), the DSM then sends the voltage to the adjustable pedal motor along circuit CPP10 (BN/BU), the voltage passes through the motor and returns to the DSM along circuit CPP09 (VT/OG). The DSM then sends the voltage back to the switch along circuit CPP09 (VT/OG) where it is grounded along circuit GD111 (BK/BU). This causes the pedal to move rearward (toward the driver).

1. B1988 Pedal Position Forward Switch Circuit Short to Battery - If during normal operation, the DSM detects battery voltage on the adjustable pedal switch forward input circuit for more than 2 minutes DTC B1988 will be set. If during the DSM on-demand self test, the DSM detects voltage on the adjustable pedal switch forward input circuit at all, DTC B1988 will be set.
2. B1989 Pedal Position Rearward Switch Circuit Short to Battery - If during normal operation, the DSM detects battery voltage on the adjustable pedal switch rearward input circuit for more than 2 minutes DTC B1989 will be set. If during the DSM on-demand self test, the DSM detects voltage on the adjustable pedal switch rearward input circuit at all, DTC B1989 will be set.

This pinpoint test is intended to diagnose the following

1. Foreign material
2. Fuse
3. Wiring, terminals or connectors
4. Adjustable pedal switch
5. Adjustable pedal potentiometer
6. Adjustable pedal motor

When the desired memory position is selected using the memory switch or the remote transmitter, the driver seat module (DSM) sends voltage to the adjustable pedal motor along circuit CPP09 (VT/OG) to move the pedal forward and along CPP10 (BN/BU) to move the pedal rearward. When voltage is sent to the motor along circuit CPP09 (VT/OG), it returns to the DSM along CPP10 (BN/BU). Likewise, when the voltage is sent to the motor along circuit CPP10 (BN/BU), it returns to the DSM along circuit CPP09 (VT/OG).

The DSM uses a Hall-effect switch attached to the pedal motor to identify the current pedal position. The DSM sends a reference voltage along circuit RPP06 (GN), through the Hall-effect switch and back to the DSM along the signal return circuit, LPP06 (YE/BU).

1. B1987 Pedal Forward/Rearward Motor Stalled - This DTC is only set during a DSM on-demand self test. During the self-test, the adjustable pedal motor will be commanded to move forward and then rearward. If the motor encounters a hard stop while moving, the DSM will attempt to move the pedals in the same direction again. If the DSM does not see any pedal movement via the Hall-effect switch during this attempt, DTC B1987 will be set.
2. B1991 Pedal Forward/Rearward Potentiometer Feedback Circuit Short to Battery - If the DSM detects battery voltage on the Hall-effect feedback circuit during normal operation or during the DSM on-demand self test, DTC B1991 will be set.
3. B2275 Pedal Forward/Rearward Potentiometer Feedback Circuit Short to Ground - If the DSM detects a short to ground on the Hall-effect feedback circuit during normal operation or during the DSM on-demand self test, DTC B2275 will be set.

When DTC B1991 or B2275 are set, the adjustable pedal motor will operate in a "jog mode". While in jog mode, the DSM will ignore any memory switch or remote transmitter inputs. The DSM will still accept input from the adjustable pedal switch, but the motor will only move in the desired direction for one second and then stop, regardless of how long the switch is held in the desired direction.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. Adjustable pedal motor
3. DSM

During moderate to heavy braking, noise from the hydraulic control unit (HCU) and pulsation in the brake pedal can be observed. Pedal pulsation coupled with noise during heavy braking or on loose gravel, bumps, wet or snowy surfaces is acceptable and indicates correct functioning of the ABS. Pedal pulsation or steering wheel nibble when the brakes are applied (frequency is proportioned to the vehicle speed) indicates a concern with a brake or suspension component.