The instrument cluster contains a high-torque type electric speedometer. Integrated circuits control the air core speedometer and the stepper motor odometer. A removable bulb and socket assembly, that inserts into the back of the instrument cluster, provides the lighting of the speedometer.
The standard instrument cluster is equipped with the following gauges:
The Canadian instrument cluster is equipped with the following gauges:
The Export instrument cluster is equipped with the following gauges:
The instrument panel design allows for the removal of all control switches from the driver's side.
The speedometer system consists of the following components:
The 1 piece instrument cluster mounts in front of the driver in the instrument panel. The instrument cluster is not serviceable. If a diagnosis leads to a malfunctioning instrument cluster, you must repair or replace the instrument cluster through an authorized service center.
Diesel applications use a VSS buffer in the speedometer system. The VSS buffer is a solid-state device that converts the analog output from the VSS to a digital signal that contains 4,000 pulses per mile for the instrument cluster.
The VSS buffer matches to the final drive and tire size of each vehicle. Replace the VSS buffer with the proper VSS buffer part number that matches the vehicle. If the final drive or tire size changes for any reason, replace the VSS buffer with the buffer that matches the new final drive or tire size. If you do not do this, the signal will not be accurate for proper speedometer/odometer calibration. An incorrect VSS buffer may also affect the following components:
The VSS buffer attaches to the bottom rear of the instrument panel carrier, to the right of the steering column.
The VSS is a permanent magnet signal generator that sends an analog signal proportional to the propeller shaft speed to the VCM (Gasoline engines), or to the VSS buffer (Diesel engines).
The VSS mounts to the transmission tailshaft extension housing. Refer to Vehicle Speed Sensor (VSS) Replacement in Automatic Transmission - 4L60E or Automatic Transmission - 4L80E.
The fuel gauge indicates the quantity of fuel in the tank when the ignition switch is in the RUN position. When the ignition switch is turned to the following positions, the pointer may come to rest at any position:
The fuel gauge measures the current from a variable resistor in the fuel tank. A float controls the resistor. When the fuel tank is full, and the ignition switch is in the RUN position, the resistance is high and the fuel gauge indicator moves to the maximum position, or FULL on the gauge face. When the fuel tank is empty the resistance is low and the fuel gauge indicator moves to the minimum position, or EMPTY on the gauge face.
Corroded connections or severed ground paths may cause the indicator to register past FULL on the gauge face. Short circuits to ground may result in the indicator resting below EMPTY.
The fuel gauge sender assembly mounts to the top of the fuel tank. A cam-type locking ring, or snap ring, retains the fuel gauge assembly. A seal is used between the fuel tank and the sender.
The fuel gauge sender assembly consists of the following components:
For fuel gauge sender replacement procedures, refer to the appropriate procedure:
The coolant temperature gauge measures the current from a variable resistance sensor in the engine coolant jacket when the ignition switch is in the RUN position.
The sensor changes resistance with the coolant temperature. As the coolant temperature increases, the resistance of the sensor decreases.
For gasoline engines, the coolant temperature sensor is near the middle of the cylinder head, on the driver's side of the vehicle. For diesel engines, the coolant temperature sender is at the front of the cylinder head, on the driver's side of the vehicle.
The oil pressure gauge indicates engine oil pressure when the ignition switch is in the RUN position.
An oil pressure sensor in the engine block changes resistance with oil pressure. On gasoline engines, the oil pressure sender is at the top rear of the engine block. On diesel engines, the oil pressure sender is on the driver side top of the engine block, under the intake manifold.
The voltmeter indicates nominal electrical system voltage. When the engine is running, the indicator should be 10-16 volts. If the indicator is not within these limits with the engine running, refer to Charging System Check in Engine Controls.
The voltmeter has a red band at each extreme end of the voltmeter's range. If the indicator rests just outside of either band, consider this normal operation. If the indicator rests inside of either band, this indicates a charging system condition.
