Pinpoint Tests AD: The Message Center Is Not Operating Correctly
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test AD: The Message Center Is Not Operating Correctly
Normal Operation
The message center displays general information about total odometer, trip odometers and compass direction information after the Instrument Cluster (IC) prove-out. With the ignition in the ON position, the message center displays important vehicle information through a constant monitoring of vehicle systems displaying potential vehicle conditions. The message center switch is hardwired to the IC through circuits CMC29 (GN/VT) and RMC27 (WH/BN). To communicate the requested switch function, each message center switch button uses a different resistance value, allowing the IC to determine which switch is pressed.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Message center switch
- IC
PINPOINT TEST AD: 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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AD1 CHECK THE MESSAGE CENTER DISPLAY OPERATION USING THE SCAN TOOL
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC display segment (SEGMENTS_2) active command. Command the display segments on. Observe the message center display.
- Does the message center display illuminate all segments?
Yes
GO to AD2.
No
GO to AD7.
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AD2 CHECK THE IC PID FOR THE MESSAGE CENTER SWITCH USING THE SCAN TOOL
- Select and monitor the IC message center switch INFO (INFO), SETUP (SETUPSW) and RESET (RES_SW) PIDs while pressing each message center switch (INFO, SETUP, and RESET).
- Do the PIDs agree with the switch position?
Yes
GO to AD7.
No
GO to AD3.
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AD3 CHECK CIRCUITS CMC29 (GN/VT) AND RMC27 (WH/BN) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: IC C220.
- Disconnect: Message Center Switch C253.
- Ignition ON.
- Measure the voltage between the IC C220-24, circuit CMC29 (GN/VT), harness side and ground; and between the IC C220-11, circuit RMC27 (WH/BN), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit in question. TEST the system for normal operation.
No
GO to AD4.
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AD4 CHECK CIRCUIT CMC29 (GN/VT) FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the IC C220-24, circuit CMC29 (GN/VT), harness side and the message center switch C253-3, circuit CMC29 (GN/VT), harness side; and between the IC C220-24, circuit CMC29 (GN/VT), harness side and ground.
- Is the resistance less than 5 ohms between the IC and the message center switch, and greater than 10,000 ohms between the IC and ground?
Yes
GO to AD5.
No
REPAIR the circuit. TEST the system for normal operation.
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AD5 CHECK CIRCUIT RMC27 (WH/BN) FOR AN OPEN OR SHORT TO GROUND
- Measure the resistance between the IC C220-11, circuit RMC27 (WH/BN), harness side and the message center switch C253-2, circuit RMC27 (WH/BN), harness side; and between the IC C220-11, circuit RMC27 (WH/BN), harness side and ground.
- Is the resistance less than 5 ohms between the IC and the message center switch, and greater than 10,000 ohms between the IC and ground?
Yes
GO to AD6.
No
REPAIR the circuit. TEST the system for normal operation.
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AD6 CHECK FOR VOLTAGE FROM THE IC
- Connect: IC C220.
- Ignition ON.
- Measure the voltage between the message center switch C269-3, circuit CMC29 (GN/VT), harness side and the message center switch C269-2, circuit RMC27 (WH/BN), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new message center switch. REFER to Message Center Switch Service and Repair. TEST the system for normal operation.
No
GO to AD7.
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AD7 CHECK FOR CORRECT IC OPERATION
- Disconnect the IC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IC 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 IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). 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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