For 1990-2009 cars

# BROKEN AMBIENT AIR TEMPERATURE SENSOR

BROKEN AMBIENT AIR TEMPERATURE SENSOR

#### VEHICLES AFFECTED: 1986 Rivieras Below VIN GU412313 -----------------

If a broken ambient air temperature sensor is encountered on a 1986 Riviera, the sensor must be replaced and relocated. A different sensor bracket has been released, Part Number 1634736, and is available from GM Parts.

The replacement sensor and new sensor bracket, need to be relocated, per the following procedure:

1. Disconnect the negative battery cable.

2. Remove the two (2) screws retaining the ambient air temperature sensor bracket to the front and centre chest metal support and remove the bracket from the vehicle.

3. Disconnect the sensor from the sensor harness.

4. Remove and retain the one (1) sensor-to-bracket screw and its speednut.

5. Loop the sensor harness back and tape to the electrical conduit behind the secondary hood latch bracket leaving 1 inch (25mm) of harness at the connector untaped: and the connector positioned neat the driver's side of the secondary hood latch bracket (See Figure 1).

6. Pry up the plastic cover on the upper tie bar near the driver's side screw of the secondary hood latch bracket; remove this screw, and install the new sensor bracket in this location. Reinstall the screw now retaining both the sensor bracket and the driver's side of the secondary hood latch bracket (See Figure 2).

7. Install the replacement sensor to the now sensor bracket using the screw and speednut retained in Step 4.

8. Connect the sensor harness to the sensor.

9. Reconnect the negative battery cable.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.