Pinpoint Test A: The Instrument Cluster (IC) Is Inoperative

Instrumentation and Warning Chimes

Pinpoint Tests

Pinpoint Test A: The Instrument Cluster (IC) Is Inoperative

Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information. Diagrams By Number

Normal Operation

The Instrument Cluster (IC) requires 3 separate voltage inputs to operate. The RUN voltage is through Central Junction Box (CJB) fuse 179, the B+ or hot at all times voltage is through CJB fuse 148 and the ACC voltage is through CJB fuse 137. The IC is grounded through a single ground circuit.

This pinpoint test is intended to diagnose the following:

- Fuse(s)
- Wiring, terminals or connectors
- IC


PINPOINT TEST A: THE IC IS INOPERATIVE

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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A1 CHECK THE IC B+ VOLTAGE SUPPLY


- Ignition OFF.
- Disconnect: IC C220b.
- Measure the voltage between the IC C220b-1, circuit 29-GG14 (OG), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to A2.

No
VERIFY the CJB fuse 148 (7.5A) is OK. If OK, REPAIR circuit 29-GG14 (OG) for an open. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. TEST the system for normal operation. Diagrams By Number

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A2 CHECK THE IC RUN VOLTAGE SUPPLY


- Ignition ON.
- Measure the voltage between the IC C220b-6, circuit 15-GG14 (GN/RD), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to A3.

No
VERIFY the CJB fuse 179 (7.5A) is OK. If OK, REPAIR circuit 15-GG14 (GN/RD) for an open. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. TEST the system for normal operation. Diagrams By Number

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A3 CHECK THE IC ACC VOLTAGE SUPPLY


- Ignition OFF.
- Disconnect: IC C220a.
- Ignition In ACC.
- Measure the voltage between the IC C220a-14, circuit 75-GG14 (YE/BU), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to A4.

No
VERIFY the SJB fuse 137 (7.5A) is OK. If OK, REPAIR circuit 75-GG14 (YE/BU) for an open. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. TEST the system for normal operation. Diagrams By Number

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A4 CHECK THE IC GROUND CIRCUIT FOR AN OPEN


- Measure the voltage between the IC C220b-1, circuit 29-GG14 (OG), harness side and the IC C220b-2, circuit 91-GG14 (BK/OG), harness side.




- Is the voltage greater than 10 volts?

Yes
GO to A5.

No
REPAIR circuit 91-GG14 (BK/OG) for an open. TEST the system for normal operation.

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A5 CHECK FOR CORRECT IC OPERATION


- Disconnect the IC connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IC 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 IC. REFER to Instrument Cluster (IC) Service and Repair. 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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