GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The DIC receives the vehicle speed information from the PCM. The PCM converts the data from the vehicle speed sensor to a 4000 pulses/mile signal. The PCM also sends a class 2 message to the DIC indicating the vehicle speed. If the DIC determines there is a loss of the vehicle speed signal from the PCM due to a vehicle speed signal circuit malfunction, a DTC sets.

Conditions for Running the DTC

    • The DIC detects a RAP 1 fuse supply voltage.
    • The ignition 1 voltage is between 9.8 volts and 16.5 volts.

Conditions for Setting the DTC

    • The DIC receives a class 2 message from the PCM indicating a vehicle speed of greater than 3 km/h (1.86 mph).
    • The DIC detects a loss of vehicle speed on the vehicle speed signal circuit.
    • The above condition is present for greater than 15 seconds.

Action Taken When the DTC Sets

The DIC stores DTC B0540 in memory.

Conditions for Clearing the DTC

    • The DTC becomes history when the fault is no longer present.
    • A history DTC clears after 100  malfunction free ignition cycles.
    • The DIC receives the clear code command from the scan tool.

Step

Action

Yes

No

Schematic Reference: Driver Information System Schematics

1

Did you perform the Driver Information Center Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Driver Information Systems

2

  1. Install a scan tool.
  2. Raise the vehicle drive wheels. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Start the engine.
  4. Place the transmission into drive for an automatic transmission or third gear for a manual transmission.
  5. With the scan tool, observe the Vehicle Speed parameter in the DIC data list.

Does the Vehicle Speed paramater indicate a vehicle speed?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Test the vehicle speed signal circuit of the DIC for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 6

Go to Step 4

4

Inspect for poor connections at the harness connector of the DIC. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 6

Go to Step 5

5

Replace the DIC. Refer to Driver Information Center Replacement .

Did you complete the replacement?

Go to Step 6

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6

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK