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B3649




DTC B3649

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 B3649 04
- Steering Wheel Scroll Wheel Left Circuit Open

DTC B3649 5A
- Steering Wheel Scroll Wheel Left Stuck

DTC B3649 08
- Steering Wheel Scroll Wheel Left Circuit Resistance Range/Performance

Diagnostic Fault Information





Circuit/System Description

The steering column control module (SCCM) supplies voltage to the audio steering wheel control multiple momentary contact switches and monitors the return signal. Each switch is associated to a set resistance value, when pressed a specific voltage drop occurs through a series of resistors unique to that switch. The SCCM identifies the selection, then sends a serial data message that is received by the component controlled, activating the feature.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

B3649 04

The SCCM detects that the left scroll wheel circuit is open.

B3649 5A

The SCCM detects that the left scroll wheel is stuck for greater than 60 seconds.

B3649 08

The SCCM detects that the left scroll wheel resistance is out of range.

Action Taken When the DTC Sets

The SCCM will ignore the switch command.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Reference Information
Schematic Reference

Steering Wheel Secondary/Configurable Control Schematics (Steering Wheel Secondary/Configurable Control Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

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

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (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 Left Steering Remote Control Status parameter while pressing and releasing the scroll wheel switch. The reading should be Menu Up and Menu Down identifying when the switch pressed, and No Key Pressed when the switch is released.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the left steering wheel control switch.
2. Ignition OFF, test for less than 2.0 ohms between the low reference circuit terminal 2 and ground.

If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the SCCM.

3. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 1 and ground.

If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the SCCM.

If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the SCCM.

4. If all circuits test normal, test or replace the left steering wheel control switch.

Component Testing

1. Disconnect the harness connector at the left steering wheel control switch.
2. Connect a DMM between terminals 1 and 2 of the left steering wheel control switch.

If any of the resistance measurements for the individual switches are not within the specified resistance values, replace the left steering wheel control switch.





Repair Instructions

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

* Steering Wheel Control Switch Assembly Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for SCCM replacement, setup, and programming