DTC Descriptor
DTC B2815: Steering Wheel Controls Illegal Resistance Value
Diagnostic Fault Information
Always perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
Circuit/System Description
The body control module (BCM) supplies 12 volts 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 BCM 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
The BCM detects a switch voltage that is higher than normal.
Action Taken When the DTC Sets
The BCM will ignore the switch command.
Conditions for Clearing the DTC
| • | The DTC will become history if the BCM no longer detects a circuit malfunction. |
| • | The history DTC will clear after 100 fault-free ignition cycles. |
| • | The DTC can be cleared with a scan tool. |
Diagnostic Aids
| • | This diagnostic is for the audio steering wheel controls. |
| • | Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly. |
| • | Review schematic when testing switch resistance values. |
Reference Information
Schematic Reference
Steering Wheel Schematics
Connector End View Reference
Electrical Information Reference
Circuit/System Verification
Ignition ON, observe the scan tool steering wheel controls (SWC) Switch Voltage parameter in the body control module (BCM) data list . Pressing the switch should read voltage present, and drop to 0 volts when released.
Circuit/System Testing
It is recommended that Component Testing is performed before Circuit Testing when diagnosing steering wheel controls.
Caution: Refer to SIR Caution in the Preface section.
- Ignition OFF, disconnect the right steering wheel control connector.
- Ignition ON, with a scan tool, verify the SWC Switch Voltage parameter is at 0 volts.
| ⇒ | If over 0 volts, test the remote radio control signal circuit for a short to voltage. If the circuits test normal, replace the BCM. |
- If all circuits test normal, refer to Component Testing.
Component Testing
Caution: Refer to SIR Caution in the Preface section.
- Ignition OFF, disconnect the harness connector at the audio steering wheel control switches.
- Test the switch for infinite resistance between the voltage supply terminal and the signal terminal with the switch in the open position.
| ⇒ | If less than infinite resistance, replace the switch. |
- Test resistance values between the voltage supply terminal and the signal terminal with the switch closed in each position and verify readings are approximate to what the schematic reads.
| ⇒ | If values do not, replace the switch. |
Repair Instructions
Always perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
