Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC B2850 01: Telescope Forward Switch Circuit Short to BatteryDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Steering Column Tilt Up Switch Signal | 1 | 1 | B2870 | -- |
Steering Column Tilt Down Switch Signal | 1 | 1 | B2875 | -- |
Steering Column Telescope Reverse Switch Signal | 2 | 2 | B2855 | -- |
Steering Column Telescope Forward Switch Signal | 2 | 2 | B2850 | -- |
1. Tilt Malfunction 2. Telescope Malfunction | ||||
Circuit Description
The memory seat module (MSM) receives voltage inputs from the tilt/telescope switch based on the position of the switch. The MSM then supplies battery voltage and a ground to the tilt or telescope motor control circuits depending on which direction of movement is requested.
Conditions for Running the DTC
The ignition ON.
Conditions for Setting the DTC
The MSM detects a telescope forward switch input for more than 30 consecutive seconds after forward movement of the motor has stopped.
Action Taken When the DTC Sets
| • | The telescope motor will be deactivated. |
| • | Memory recall functions will be disabled. |
Conditions for Clearing the DTC
| • | A current DTC will clear when the failed switch input is no longer active. |
| • | A history DTC will clear after 100 ignition cycles. |
Diagnostic Aids
An intermittently stuck telescope switch may cause this DTC to set.
Reference Information
Schematic Reference
Tilt/Telescoping Steering Column Schematics
Connector End View Reference
Steering Wheel and Column Connector End Views
Description and Operation
Steering Wheel and Column Description and Operation
Electrical Information Reference
| • | Circuit Testing |
| • | Wiring Repairs |
Scan Tool Reference
Circuit/System Verification
Ignition ON, view the scan tool Telescope Forward Switch parameter while cycling the tilt/telescope switch between the neutral and TELESCOPE IN position. The parameter should change between Active and Inactive.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the tilt/telescope switch.
- Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 4 and ground.
- Verify the scan tool Telescope Forward Switch parameter is Inactive.
- Install a 3A fused jumper wire between the signal circuit terminal 3 and the B+ circuit terminal 4. Verify the scan tool Telescope Forward Switch parameter is Active.
- If all circuit test normal, test or replace the tilt/telescope switch.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If not the specified value, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the MSM. |
| ⇒ | If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM. |
Component Testing
Tilt/Telescope Switch
- Ignition OFF, disconnect the harness connector at the tilt/telescope switch.
- Test for infinite resistance between the following terminals with the switch in the neutral position:
- Test for less than 1 ohm or resistance between the B+ terminal 4 and the signal terminal 5 with the switch in the TILT UP position.
- Test for less than 1 ohm or resistance between the B+ terminal 4 and the signal terminal 1 with the switch in the TILT DOWN position.
- Test for less than 1 ohm or resistance between the B+ terminal 4 and the signal terminal 2 with the switch in the TELESCOPE OUT position.
- Test for less than 1 ohm or resistance between the B+ terminal 4 and the signal terminal 3 with the switch in the TELESCOPE IN position.
| • | B+ terminal 4 and signal terminal 5 |
| • | B+ terminal 4 and signal terminal 1 |
| • | B+ terminal 4 and signal terminal 2 |
| • | B+ terminal 4 and signal terminal 3 |
| ⇒ | If less than the specified range, replace the tilt/telescope switch. |
| ⇒ | If greater than the specified range, replace the tilt/telescope switch. |
| ⇒ | If greater than the specified range, replace the tilt/telescope switch. |
| ⇒ | If greater than the specified range, replace the tilt/telescope switch. |
| ⇒ | If greater than the specified range, replace the tilt/telescope switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for MSM replacement, setup, and programming |
