Diagnostic Instructions
DTC Descriptors
DTC B1529 03: Device Voltage Reference Output Circuit Voltage Below Threshold
DTC B1529 07: Device Voltage Reference Output Circuit Voltage Above Threshold
Circuit/System Description
The body control module (BCM) 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 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
B1529 03
The BCM senses the supply voltage circuit is below 1.0 volt after 5 seconds
B1529 07
The BCM senses the supply voltage circuit above 24.5 volts after 5 seconds.
Action Taken When the DTC Sets
The BCM 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. |
Diagnostic Aids
| • | Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly. |
| • | If a single switch function is inoperative, test the suspect switch. Refer to component testing. |
| • | DTC B1529 07 may be set if the vehicle is equipped with dual batteries that is incorrectly hooked up, or the vehicle is jump started by a tow truck with dual batteries. |
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
Circuit/System Verification
- Verify DTC B1529 07 is not set.
| ⇒ | If the DTC is set, clear the DTC and operate the vehicle within the Conditions for Running the DTC. If the DTC resets, refer to
Charging System Test
. |
- Ignition ON, observe the scan tool SWC Bank 1 status while pressing and releasing the switches. The reading should be SW1-SW7 identifying the switch pressed, and Idle when released.
Circuit/System Testing
Important: 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 harness connector at the left steering wheel control switch.
- Ignition ON, test for ignition voltage between the ignition circuit terminal 1 and ground.
| ⇒ | If less than the specified value, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
- Test for 0 volts between the signal circuit terminal 4 and ground.
| ⇒ | If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
- Test for ignition voltage between the ignition circuit terminal 1 and the signal circuit terminal 4.
| ⇒ | If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
- Install a 3A fused jumper wire at the ignition circuit terminal 1 and the signal circuit terminal 5.
- Disconnect the harness connector at the right steering wheel control switch.
- Test for ignition voltage between the signal circuit terminal 1 and ground.
| ⇒ | If less than the specified value, test the signal circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the BCM. |
- Test for 0 volts between the circuit terminal 4 and ground.
| ⇒ | If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
- Test for ignition voltage between the ignition circuit terminal 1 and the signal circuit terminal 4.
| ⇒ | If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
- If all circuits test normal, test or replace the steering wheel control switch.
Component Testing
Caution: Refer to SIR Caution in the Preface section.
- Ignition OFF, disconnect the harness connector at the left steering wheel control switch.
- Test the for less than 2,500 ohms between the ignition circuit terminal 1 and the signal circuit terminal 5.
| ⇒ | If not the specified range, replace the steering wheel control switch. |
- Test for infinite resistance between the ignition circuit terminal 1 and the signal terminal 4 with the switch in the open position.
| ⇒ | If not the specified range, replace the steering wheel control switch. |
- Test the for less than 2,500 ohms between the ignition circuit terminal 1 and the signal terminal 4 with the switch in the closed position.
| ⇒ | If greater than the specified range, replace the left steering wheel control switch. |
- Disconnect the harness connector at the right steering wheel control switch.
- Test for infinite resistance between the signal circuit terminal 1 and the signal circuit terminal 4 with the switch in the open position.
| ⇒ | If not the specified range, replace the steering wheel control switch. |
- Test for less than 3,000 ohms between the signal terminal 1 and the signal circuit terminal 4 with the switch in the closed position.
| ⇒ | If greater than the specified range, replace the steering wheel control switch. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
