Pinpoint Test L: The Steering Wheel Controls Are Inoperative/Do Not Operate Correctly

Information and Entertainment System

Pinpoint Tests

Pinpoint Test L: The Steering Wheel Controls Are Inoperative/Do Not Operate Correctly

Refer to Wiring Diagrams Set 130, Audio System for schematic and connector information. Diagrams By Number

Normal Operation

Two different steering wheel switch configurations are available, depending on whether the vehicle is equipped with the SYNC system.

On vehicles without the SYNC system, all of the steering wheel control switches are wired to the Audio Control Module (ACM). The steering wheel controls are: VOL+, VOL-, SEEK+, SEEK-, and MEDIA. The SEEK+ and SEEK- switches are represented by arrows.

For vehicles equipped with the SYNC system, the steering wheel controls are: VOL+, VOL-, SEEK+, SEEK-, MEDIA, VOICE, PHONE, and OK. The SEEK+ and SEEK- switches are represented by arrows, the VOICE switch is represented by an icon of someone speaking, and the PHONE switch is represented by an icon of a phone with an up-and-down arrow. The VOICE, PHONE, and OK switches are wired to the Accessory Protocol Interface Module (APIM), while the remaining switches are wired to the ACM.

For all switches, a reference voltage is sent from the appropriate module to the steering wheel controls. When a switch is pressed, the voltage is routed through a specific resistor value for each function. The module provides the ground for the reference voltage. The module uses this reference voltage to determine which control input function has been selected.

B1117-B2404:

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Steering wheel controls
- Clockspring
- ACM
- APIM (if equipped)

PINPOINT TEST L: THE STEERING WHEEL CONTROLS ARE INOPERATIVE/DO NOT OPERATE CORRECTLY

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

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L1 CHECK THE VEHICLE CONTENT

- Determine if the vehicle is equipped with the SYNC system.
- Is the vehicle equipped with the SYNC system?

Yes
GO to L3.

No
GO to L2.

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L2 CHECK THE INOPERATIVE SWITCH(ES) - VEHICLES WITHOUT THE SYNC SYSTEM

- Operate the audio system in radio tuner (AM/FM) mode.
- Press each individual steering wheel control switch and verify the individual switch operation.
- Are all of the steering wheel controls inoperative?

Yes
GO to L4.

No
INSTALL new steering wheel controls. REFER to Steering Wheel Controls Service and Repair. CLEAR any DTCs present. TEST the system for normal operation.

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L3 CHECK FOR INOPERATIVE SWITCH(ES) TO THE ACM - VEHICLES WITH THE SYNC SYSTEM

- Operate the audio system in radio tuner (AM/FM) mode.
- Press the VOL+, VOL-, SEEK+, SEEK-, and MEDIA buttons.
- Do the VOL+, VOL-, SEEK+, SEEK-, and MEDIA buttons operate correctly?

Yes
GO to L7.

No
If only one button is inoperative, INSTALL new steering wheel controls. REFER to Steering Wheel Controls Service and Repair. CLEAR any DTCs present. TEST the system for normal operation.

If all of the ACM-controlled steering wheel controls are inoperative, GO to L4.

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L4 MONITOR THE ACM-CONTROLLED STEERING WHEEL CONTROLS PIDs

- Enter the following diagnostic mode on the scan tool: ACM DataLogger.
- Monitor the steering wheel controls PIDs while pressing each steering wheel controls button as follows:

- Do the PID values agree with the switch position?

Yes
GO to L12.

No
If only one PID value is incorrect or the PID value always reads one particular switch position (except no buttons pressed), INSTALL new steering wheel controls. REFER to Steering Wheel Controls Service and Repair. CLEAR any DTCs present. TEST the system for normal operation.

Otherwise, GO to L5.

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L5 CHECK THE CIRCUITS TO THE CLOCKSPRING FOR A SHORT TO VOLTAGE - ACM-CONTROLLED SWITCHES

- Disconnect: Clockspring C218.
- Ignition ON.
- Measure the voltage between the ACM C240a-18, circuit VME14 (GY/YE), harness side and ground; and between the ACM C240a-19, circuit RME24 (BU/WH), harness side and ground.

- Is any voltage present?

Yes
REPAIR the circuit in question. CLEAR the DTCs. TEST the system for normal operation.

No
GO to L6.

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L6 CHECK THE CIRCUITS TO THE CLOCKSPRING FOR AN OPEN OR SHORT TO GROUND - ACM-CONTROLLED SWITCHES

- Ignition OFF.
- Measure the resistance between the ACM, harness side and the clockspring, harness side; and between the ACM, harness side and ground as follows:

- Do the PID values agree with the switch positions?

Yes
GO to L13.

No
If only one PID value is incorrect or the PID value always reads one particular switch position (except no buttons pressed), INSTALL new steering wheel controls. REFER to Steering Wheel Controls Service and Repair. CLEAR any DTCs present. TEST the system for normal operation.

Otherwise, GO to L9.

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L9 CHECK THE CIRCUITS TO THE CLOCKSPRING FOR A SHORT TO VOLTAGE - APIM-CONTROLLED SWITCHES

- Disconnect: Clockspring C218.
- Ignition ON.
- Measure the voltage between the APIM C2298-14, circuit VME54 (BU/OG), harness side and ground; and between the APIM C2298-15, circuit RME54 (WH/VT), harness side and ground.

- Is any voltage present?

Yes
REPAIR the circuit in question. CLEAR the DTCs. TEST the system for normal operation.

No
GO to L10.

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L10 CHECK THE CIRCUITS TO THE CLOCKSPRING FOR AN OPEN OR SHORT TO GROUND - ACM-CONTROLLED SWITCHES

- Ignition OFF.
- Measure the resistance between the APIM, harness side and the clockspring, harness side; and between the APIM, harness side and ground as follows:

- Is the resistance less than 5 ohms between the ACM and the clockspring, and greater than 10,000 ohms between the ACM and ground?

Yes
GO to L11.

No
REPAIR the circuit in question. CLEAR the DTCs. TEST the system for normal operation.

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L11 ISOLATE THE STEERING WHEEL CONTROLS

- Connect: Clockspring C218.
- Connect: ACM C240a.
- Connect: APIM C2298.
- Install new steering wheel controls. Refer to Steering Wheel Controls Service and Repair.
- Operate the system and determine if the concern is still present.
- Is the concern still present?

Yes
INSTALL a new clockspring. CLEAR any DTCs present. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern was caused by inoperative steering wheel controls. CLEAR any DTCs present. TEST the system for normal operation.

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L12 CHECK FOR CORRECT ACM OPERATION

- Connect: Clockspring C218.
- Disconnect all the ACM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the ACM connectors and make sure they seat correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?

Yes
INSTALL a new ACM. REFER to Audio Control Module (ACM) Audio Control Module (ACM). TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

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L13 CHECK FOR CORRECT APIM OPERATION

- Connect: Clockspring C218.
- Disconnect the APIM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the APIM connector and make sure it seats correctly.
- Wait 2 minutes for the APIM to re-initialize.
- Operate the system and determine if the concern is still present.
- Is the concern still present?

Yes
INSTALL a new APIM. REFER to Accessory Protocol Interface Module (APIM) Accessory Protocol Interface Module (APIM). TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

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