The G-sensor is used only on the AWD vehicles. It is mounted under the rear seat cushion, directly between the seat belt heads on 1991-94 vehicles. On 1995-98 vehicles, the sensor is mounted behind the front floor console. The sensor transmits acceleration and deceleration information to the Anti-lock control unit. This data is used in conjunction with individual wheel speed and engine data, allowing the controller to determine the approximate road friction. This friction factor is then used to compute the proper control of the solenoid valves.
See Figures 1 and 2
- Remove the sensor and position on a level surface.
- Connect an ohmmeter between the terminal of the sensor and verify there is continuity.
- Tilt the sensor slowly 30 degrees in the direction of vehicle travel and verify the ohmmeter reads infinity.
- Tilt the sensor slowly 30 degrees toward the rear of the vehicle and verify the ohmmeter reads infinity.
- If not as specified, replace the G sensor.
See Figures 3 and 4
- Detach the G-sensor connector, then connect the test harness set MB991348, or equivalent, between the terminals of the detached connector.
- Turn the ignition switch ON and take a reading of the output voltage between terminals 2 and 3. The reading should be 2.4-2.6 volts.
- With the special tool still connected, secure the G-sensor so that the front mark on the sensor mounting surface is facing straight down, then take a reading of the output voltage between terminals 2 and 3. The reading should be 3.3-3.7 volts.
- If the voltage is outside the standard value, after checking to be sure the wiring is operating properly, replace the G-sensor.
REMOVAL & INSTALLATION
See Figures 5 and 6
- Insure that the ignition switch is OFF throughout the procedure.
- Disconnect the negative battery cable.
- For 1991-94 vehicles, remove the rear seat cushion.
- For 1995-98 vehicles, remove the radio/tape/CD player assembly, as outlined in Chassis Electrical of this repair guide.
- Disconnect the wiring harness from the G-sensor.
- Remove the retaining bolts and remove the sensor.
- Position the sensor on the mounting bracket. Tighten the retaining bolts.
- Connect the electrical harness.
- Install the rear seat cushion or radio, as applicable.
- Connect the negative battery cable.