GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The instrument cluster receives a vehicle speed input from the Vehicle Speed Sensor (VSS) from circuit 817. This signal is used to drive the speedometer and the odometer of the instrument cluster. The instrument cluster will compare the VSS data with a sixteen-point look-up table to determine needle deflection. A smooth filter is used to secure a continuous response. The season odometer displays the total accumulated kilometers (miles) of the vehicle. This value is permanently stored in the Electronically Erasable Programmable Read Only Memory (EEPROM) of the instrument cluster. The trip odometer displays the accumulated kilometers (miles) to the tenths of a kilometer (mile) since the last reset. This value is stored in Keep Alive Memory (KAM) of the instrument cluster.

Conditions for Setting the DTC

The instrument cluster performs an internal check on the operation of the speedometer and odometer, and detects an internal fault in the speedometer and/or odometer.

Action Taken When the DTC Sets

    • The instrument cluster stores DTC B0570 in memory.
    • Odometer displays the word Error.

Conditions for Clearing the DTC

    • Under all fault conditions, the ignition switch must be cycled from the on to the off position, back to the on position before this DTC can change from current to history.
    • A history DTC will clear after 100 drive cycles if the condition for this DTC is no longer present.
    • Use a scan tool.

Diagnostic Aids

The following conditions may cause an intermittent malfunction to occur:

   • 

A voltage spike in circuit 817.

   • 

Illegal tampering with the instrument cluster.

   • 

Improperly installed aftermarket equipment.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Always perform the instrument cluster diagnostic system check before attempting to diagnose this DTC.

  2. This repair procedure requires instrument cluster replacement.

Step

Action

Value(s)

Yes

No

1

Was the instrument cluster diagnostic system check performed?

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Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

Replace the instrument cluster. Refer to Instrument Cluster Replacement for service procedure.

Is the repair complete?

--

Go to Diagnostic System Check - Instrument Cluster

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