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. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Steering Wheel Controls Signal | 1 | 1 | -- | -- |
Right Steering Wheel Scroll 1 Signal | 1 | B2815 04 | -- | -- |
Right Steering Wheel Scroll 2 Signal | 1 | B2815 04 | -- | -- |
Left Steering Wheel Scroll 1 Signal | 1 | B2815 04 | -- | -- |
Left Steering Wheel Scroll 2 Signal | 1 | B2815 04 | -- | -- |
Steering Wheel Controls Low Reference | 1 | B2815 04 | -- | -- |
1. Steering wheel controls inoperative. | ||||
Circuit/System Description
The instrument panel cluster (IPC) supplies a regulated voltage supply to the steering wheel control switches and monitors the return signal. Each switch state is associated with a specific resistance value. When a switch is depressed a specific voltage drop occurs across the resistor unique to that switch. The IPC is able to identify which switch was depressed by recognising the voltage drop associated with that switch and responds to the selected request.
Reference Information
Schematic Reference
Steering Wheel Secondary/Configurable Control Schematics
Connector End View Reference
Description and Operation
Steering Wheel Controls Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, while depressing the individual push button steering wheel control switches, observe the scan tool and verify the status of the individual steering wheel control switches. The following values should display depending on which switch is depressed.
Depressed | Displayed |
|---|---|
Right Scroll Wheel | Mute |
Phone/Talk | Phone A |
Call End | Phone B |
Source | Mode |
Trip | Trip time |
| • | While rotating the individual scroll wheel control switches UP multiple times, the value of the Left Source Button or the Right Source Button parameter starts counting until a maximum value of 127 counts are shown. When the switch is released, the Left Source Button or the Right Source Button parameter restarts from 0. |
| • | While rotating the individual scroll wheel control switches DOWN multiple times, the value of the Left Source Button or the Right Source Button parameter starts counting until a minimum value of -127 counts are shown. When the switch is released, the Left Source Button or the Right Source Button parameter restarts from 0. |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the steering wheel switch assembly.
- Test for less than 5 ohms between the low reference circuit terminal 5 and ground.
- Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 6 and ground.
- Test for 4.8-5.2 volts between the signal circuit terminals listed below and ground.
- If all circuits test normal, replace the steering wheel control switch assembly.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the IPC. |
| ⇒ | 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 IPC. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the IPC. |
| • | Right Steering Wheel Scroll 2 terminal 1. |
| • | Right Steering Wheel Scroll 1 terminal 2. |
| • | Left Steering Wheel Scroll 1 terminal 3. |
| • | Left Steering Wheel Scroll 2 terminal 4. |
| ⇒ | If less than the specified range, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the IPC. |
| ⇒ | If greater than the specified range, test the appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the IPC. |
Component Testing
- Ignition OFF, disconnect the harness connector at the steering wheel switch assembly.
- Test for 0.5-O.L. ohms between the scroll wheel terminals listed below, while rotating each steering wheel scroll wheel several times through its full range of motion.
- Test the resistance between the signal terminal 6 and the low reference terminal 5 while depressing the appropriate steering wheel controls switch button listed below.
| • | right steering wheel scroll wheel terminal 1 and terminal 2. |
| • | left steering wheel scroll wheel terminal 3 and terminal 4. |
| ⇒ | If not within the specified range or is erratic, replace the steering wheel switch. |
| ⇒ | If not the specified value, replace the steering wheel switch. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
|---|---|---|
Mute | 98 Ohm | 104 Ohm |
Phone/Talk | 247 Ohm | 253 Ohm |
Disc Change | 426 Ohm | 434 Ohm |
Audio | 646 Ohm | 653 Ohm |
Trip | 975 Ohm | 983 Ohm |
Call End | 3.73k Ohm | 3.79k Ohm |
No Switch Pressed | 7.01k Ohm. | 7.30k Ohm. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
