GM Service Manual Online
For 1990-2009 cars only

Circuit Description

Telescopic Steering column settings are stored in the DPM. The DPM measures and stores the steering column position by using a position sensor, which is an internal part of the telescoping actuator. The DPM provides the position sensor with a 5 volt reference and ground. The DPM monitors the position sensor signal voltage, which ranges from 0.25-4.75 volts depending on the steering column position. the steering column position sensor becomes active only when the DPM detects a steering column switch input through GMLAN by IPM.

DTC Descriptors

This diagnostic procedure supports the following DTC:

DTC B2860 Telescope Position Sensor

Conditions for Setting the DTC

The steering column position sensor signal, to the SCM, is less than 0.25 volt or greater than 4.75 volts for 2 seconds or more.

Action Taken When the DTC Sets

    • A history DTC B2860 is stored in the DPM memory.
    •  This DTC can only be set as a history code even if the malfunction is current.
    • No driver warning message will be displayed for this DTC.
    • The memory operation/function of the faulted position sensor is disabled.

Conditions for Clearing the DTC

The steering column position sensor input, to the DPM, is within 0.25-4.75 volts for 2 seconds or more.

Diagnostic Aids

    • If the DTC does not reset after the code is cleared the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur. Refer to Testing for Intermittent Conditions and Poor Connections.
    • The following conditions may also cause an intermittent malfunction:
   • 

There is an intermittent open, short to ground, or short to voltage in steering column telescope motor signal circuit.

   • 

The steering column position sensor is open or shorted internally.

    • If the DPM is unable to determine the correct steering column position, limited manual operation of the telescopic steering column will be functional, but the DPM will be unable to recall the correct memory settings.
    • Using a scan tool, select DPM data display and monitor the Column Position Feedback data. Operate the steering column in both directions while monitoring the position sensor data. The voltage should range from 0.25-4.78 volts depending on the steering column position.

Test Description

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

  1. This step tests for the proper operation of the circuit in the high voltage range.

  1. This step tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.

  2. This step tests for a short to ground in the 5-volt reference circuit.

Step

Action

Values

Yes

No

Schematic Reference: Tilt/Telescoping Steering Column Schematics

Connector End View Reference: Steering Wheel and Column Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn ON the ignition, with the engine OFF.
  2. Observe the Column Position Feedback data parameter in the Driver Position Module Column Info list with a scan tool.

Does the scan tool indicate that the Column Position Feedback data parameter is within the specified range?

0.25-4.75V

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the telescoping sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the Column Position Feedback data parameter with the scan tool.

Does the scan tool indicate that the Column Position Feedback data parameter is greater than the specified value?

4.75V

Go to Step 4

Go to Step 8

4

  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the signal circuit of the telescoping sensor and the low reference circuit of the telescoping sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the Column Position Feedback data parameter with the scan tool.

Does the scan tool indicate that the Column Position Feedback data parameter is less than the specified value?

0.25V

Go to Step 5

Go to Step 9

5

  1. Key off
  2. Connect the fused jumper.
  3. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the telescoping sensor and the signal circuit of the telescoping sensor.
  4. Turn ON the ignition, with the engine OFF.
  5. Observe the Column Position Feedback data parameter with the scan tool.

Does the scan tool indicate that the Column Position Feedback data parameter is greater than the specified value?

4.75V

Go to Step 7

Go to Step 6

6

Test the 5-volt reference circuit of the telescoping sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

7

Test the 5-volt reference circuit of the telescoping sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testingand Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 11

8

Test the signal circuit of the telescoping sensor for a short to ground. Refer to Circuit Testingand Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

9

Test the signal circuit of the telescoping sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testingand Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 10

10

Test the low reference circuit of the telescoping sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

11

Inspect for poor connections at the harness connector of the telescoping sensor. Refer to Testing for Intermittent Conditions and Poor Connectionsand Connector Repairs.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

12

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

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

Replace the telescoping sensor. Refer to Telescope Actuator Assembly Replacement.

Did you complete the replacement?

--

Go to Step 15

--

14

Replace and set the DPM. Refer to Position The Column Fully Up .

Did you complete the replacement and setup?

--

Go to Step 15

--

15

  1. Clear the DTCs with the scan tool.
  2. Operator the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC B2860 reset?

--

Go to Step 2

System OK