GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The internal fault detection of the electronic compass module is handled by the instrument panel cluster (IPC). The compass information is sent to the IPC via 2 discreet wire inputs from the electronic compass module. The IPC displays compass information in the driver information center (DIC). The IPC sets DTC B0933 when either compass sensor circuit is shorted to ground.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B0933 Compass Sensor Circuit Low

Conditions for Running the DTC

The instrument panel cluster (IPC) monitors the analog input values at power up.

Conditions for Setting the DTC

The IPC detects that either compass discreet circuits is shorted to ground.

Action Taken When the DTC Sets

The DTC will be set and stored in non-volatile memory.

Conditions for Clearing the DTC

    • The DTC will become history when a power cycle has been performed and the fault is not detected by the IPC.
    • The history DTC clears after 100 fault-free ignition cycles.
    • The DIC receives the clear code command from the scan tool.

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics or Driver Information System Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn OFF the ignition.
  2. Disconnect the compass module.
  3. Connect a test light between the compass sensor circuit and the compass ignition 1 signal circuit.
  4. Turn ON the ignition.

Does the test light illuminate?

Go to Step 4

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Connect a test light between the compass ignition 1 signal circuit and the compass ground circuit.
  3. Turn ON the ignition.

Does the test light illuminate?

Go to Step 5

Go to Step 6

4

Test the compass sensor circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 5

5

Test the compass sensor return circuit for an open, for a short to ground or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 8

6

Test the compass ignition 1 signal circuit for an open or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 7

7

Test the compass ground circuit for an open or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 9

8

Inspect for poor connections at the harness connector of the instrument panel cluster (IPC). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

9

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

Did you find and correct the condition?

Go to Step 12

Go to Step 11

10

Replace the IPC. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

--

11

Replace the electronic compass module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming..

Did you complete the replacement?

Go to Step 12

--

12

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

Does the DTC reset?

Go to Step 2

System OK