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B2858




DTC B2853, B2858, B2873, or B2878

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptors
DTC B2853
- Telescope Forward Switch Circuit High

DTC B2858
- Telescope Rearward Switch Circuit High

DTC B2873
- Tilt Up Switch Circuit High

DTC B2878
- Tilt Down Switch Circuit High

Diagnostic Fault Information





Circuit/System Description

The memory seat module - driver receives voltage inputs from contacts inside the tilt/telescoping switch. The memory seat module - driver then supplies battery voltage to the tilt actuator up or down circuit, or the telescoping drive motor forward or reverse circuit depending on which direction of movement is requested. Both motors are reversible and voltage is applied to either circuit to accomplish movement in opposite directions. The memory seat module - driver monitors the position and movement of the tilt actuator and telescoping drive motor on the sensor signal circuits.

Conditions for Running the DTC

Ignition ON

Conditions for Setting the DTC

The memory seat module - driver detects a switch input for more than 30 consecutive seconds after movement of the motor in the requested direction has stopped.

Action Taken When the DTC Sets

* The motor that is being driven by the failed switch 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* A current DTC will clear when the failed switch input is no longer active.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 switch can cause this DTC to set. Also, the driver can cause this DTC to set by holding the switch for 30 seconds after the column reaches the end of its travel.

Reference Information
Schematic Reference

Column Lock Schematics (Column Lock Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Steering Wheel and Column Description and Operation (Description and Operation)
Electrical Information Reference

* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Circuit Testing (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Tilt Up Switch, Tilt Down Switch, Telescope Forward Switch, and Telescope Rearward Switch parameters in the Driver Position Module Data Display. The reading should be Inactive for all 4 parameters when the switch is not pressed.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector X2 at the memory seat module - driver.
2. Ignition OFF, test for less than 1 volt on each of the switch signal circuits terminals E9, E10, E11, and E12.

If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the tilt/telescope switch.

3. If all circuits test normal, test or replace the memory seat module - driver.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Telescope Actuator Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for memory seat module - driver replacement, setup, and programming