For 1990-2009 cars

### 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 Descriptors

DTC B2815 04: Steering Wheel Switch Open Circuit
DTC B2815 59: Steering Wheel Switch Stuck

### 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.

### Conditions for Running the DTC

• | The system voltage is between 9-16 volts.

• | The ignition is ON.

### Conditions for Setting the DTC

#### DTC B2815 04

The IPC detects an open in the steering wheel circuits for more than 5 seconds.

#### DTC B2815 59

The IPC detects a stuck steering wheel switch for more than 3 minutes.

### Action Taken When the DTC Sets

• | The IPC will not acknowledge driver requested inputs from the steering wheel switch.

• | A stuck steering wheel switch will be unable to send driver requests to the IPC.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present.

• | The DTC can be cleared using a scan tool.

### Reference Information

#### Schematic Reference

Steering Wheel Secondary/Configurable Control Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Steering Wheel Controls Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### 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

Note: If DTC B2815 59 is set the steering wheel switch component test should be performed prior to continuing with component testing below.

1. Ignition OFF, disconnect the harness connector at the steering wheel switch assembly.
2. Test for less than 5 ohms between the low reference circuit terminal 5 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 IPC.

3. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 6 and ground.

⇒ | 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.

4. Test for 4.8-5.2 volts between the signal circuit terminals listed below and ground.

• | 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.

5. If all circuits test normal, replace the steering wheel control switch assembly.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the steering wheel switch assembly.
2. 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.

• | 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.

3. 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.

⇒ | 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.

• | Steering Wheel Control Switch Assembly Replacement

• | Control Module References for BCM replacement, setup, and programming