Pinpoint Tests AP: The Message Center Is Not Operating Correctly
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test AP: The Message Center Is Not Operating Correctly
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information. Diagrams By Number
Normal Operation
The message center functionality is controlled through the message center switch (part of the LH steering wheel switch), which is hardwired to the Instrument Panel Cluster (IPC) through input and return circuits. There are 3 message center switch buttons (base IPC) or 5 message center switch buttons (optional IPC). Each button operates a unique switch within the message center switch portion of the LH steering wheel switch assembly using a different resistance value associated with each specific button. The IPC sends out a reference voltage to the LH steering wheel switch on the input circuit and monitors the voltage drop when a message center switch button is pressed. The voltage drop varies depending upon the resistance of the specific button pressed, providing indication to the IPC, which switch is pressed.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Message center switch (part of the LH steering wheel switch)
- Clockspring
- IPC
PINPOINT TEST AP: THE MESSAGE CENTER IS NOT OPERATING 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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AP1 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST
- Retrieve the recorded IPC DTCs from the self-test.
- Are any DTCs recorded?
Yes
For DTC B1A82:09, INSTALL a new LH steering wheel switch. REFER to Steering Column Switches Steering Wheel Switch. CLEAR the DTC. REPEAT the self-test. For DTC B1A82:11 or DTC B1A82:13, GO to AP2. For all other DTCs, REFER to DTC Charts.
No
For the 3-button message center switch (base IPC), GO to AP9. For the 5-button message center switch (optional IPC), GO to AP2.
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AP2 CHECK THE IPC OUTPUT AT THE LH STEERING WHEEL SWITCH
- Ignition OFF.
- Disconnect: LH Steering Wheel Switch C2998.
- Ignition ON.
- Measure the voltage between the LH steering wheel switch C2998-5, circuit CMC29 (GN/TN), harness side and the LH steering wheel switch C2998-6, circuit RMC27 (WH/VT), harness side.
- Is the voltage approximately 5 volts?
Yes
INSTALL a new LH steering wheel switch. REFER to Steering Column Switches Steering Wheel Switch. CLEAR the DTCs. REPEAT the self-test.
No
GO to AP3.
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AP3 CHECK THE MESSAGE CENTER SWITCH SIGNAL CIRCUIT BETWEEN THE LH STEERING WHEEL SWITCH AND THE LOWER CLOCKSPRING FOR AN OPEN AND A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Lower Clockspring C218a.
- Measure the resistance between the LH steering wheel switch C2998-5, circuit CMC29 (GN/TN), harness side and the lower clockspring pin 3, component side; and between the LH steering wheel switch C2998-5, circuit CMC29 (GN/TN), harness side and ground.
- Is the resistance less than 5 ohms between the LH steering wheel switch and the clockspring, and greater than 10,000 ohms between the LH steering wheel switch and ground?
Yes
GO to AP5.
No
GO to AP4.
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AP4 CHECK THE MESSAGE CENTER SWITCH SIGNAL CIRCUIT BETWEEN THE LH STEERING WHEEL SWITCH AND THE UPPER CLOCKSPRING FOR AN OPEN AND A SHORT TO GROUND
- Remove the driver air bag. Refer to Supplemental Restraint System Driver Air Bag Module.
- Disconnect: Lower Clockspring C218b.
- Measure the resistance between the LH steering wheel switch C2998-5, circuit CMC29 (GN/TN), harness side and the upper clockspring C218b-1, circuit CMC29 (GN/TN), harness side; and between the LH steering wheel switch C2998-5, circuit CMC29 (GN/TN), harness side and ground.
- Is the resistance less than 5 ohms between the LH steering wheel switch and the clockspring, and greater than 10,000 ohms between the LH steering wheel switch and ground?
Yes
INSTALL a new clockspring. REFER to Supplemental Restraint System Service and Repair. CLEAR the DTC. REPEAT the self-test
No
INSTALL a new steering wheel. REFER to Steering Column Steering Wheel. CLEAR the DTC. REPEAT the self-test.
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AP5 CHECK THE MESSAGE CENTER SWITCH RETURN CIRCUIT BETWEEN THE LH STEERING WHEEL SWITCH AND THE LOWER CLOCKSPRING FOR AN OPEN
- Measure the resistance between the LH steering wheel switch C2998-6, circuit RMC27 (WH/VT), harness side and the lower clockspring pin 2, component side.
- Is the resistance less than 5 ohms?
Yes
GO to AP7.
No
GO to AP6.
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AP6 CHECK THE MESSAGE CENTER SWITCH RETURN CIRCUIT BETWEEN THE LH STEERING WHEEL SWITCH AND THE UPPER CLOCKSPRING FOR AN OPEN
- Remove the driver air bag. Refer to Supplemental Restraint System Driver Air Bag Module.
- Disconnect: Lower Clockspring C218b.
- Measure the resistance between the LH steering wheel switch C2998-6, circuit RMC27 (WH/VT), harness side and the upper clockspring C218b-2, circuit RMC27 (WH/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new clockspring. REFER to Supplemental Restraint System Service and Repair. CLEAR the DTC. REPEAT the self-test
No
INSTALL a new steering wheel. REFER to Steering Column Steering Wheel. CLEAR the DTC. REPEAT the self-test.
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AP7 CHECK THE MESSAGE CENTER SWITCH SIGNAL CIRCUIT BETWEEN THE IPC AND THE LOWER CLOCKSPRING FOR AN OPEN AND A SHORT TO GROUND
- Disconnect: IPC C220.
- Measure the resistance between the IPC C220-11, circuit CMC29 (GN/VT), harness side and the lower clockspring C218a-3, circuit CMC29 (GN/VT), harness side; and between the IPC C220-11, circuit CMC29 (GN/TN), harness side and ground.
- Is the resistance less than 5 ohms between the IPC and the clockspring, and greater than 10,000 ohms between the IPC and ground?
Yes
GO to AP8.
No
REPAIR circuit CMC29 (GN/VT) for an open or short to ground. CLEAR the DTC. REPEAT the self-test.
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AP8 CHECK THE MESSAGE CENTER SWITCH RETURN CIRCUIT BETWEEN THE IPC AND THE LOWER CLOCKSPRING FOR AN OPEN
- Measure the resistance between the IPC C220-24, circuit RMC27 (WH/VT), harness side and the lower clockspring C218a-2, circuit RMC27 (WH/VT), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to AP10.
No
REPAIR circuit RMC27 (WH/VT) for an open or short to ground. CLEAR the DTC. REPEAT the self-test.
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AP9 CHECK FOR VOLTAGE FROM THE IPC
- Disconnect: LH Steering Wheel Switch C2998.
- Ignition ON.
- Measure the voltage between the LH steering wheel switch C2998-5, circuit CMC29 (GN/TN), harness side and the LH steering wheel switch C2998-6, circuit RMC27 (WH/VT), harness side and ground.
- Is the voltage approximately 5 volts?
Yes
INSTALL a new LH steering wheel switch. REFER to Steering Column Switches Steering Wheel Switch. TEST the system for normal operation.
No
GO to AP10.
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AP10 CHECK FOR CORRECT IPC OPERATION
- Disconnect the IPC) connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IPC connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). 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.
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