Pinpoint Test J: The In-Dash Computer Is Inoperative

Ford Work Solutions(TM)

Pinpoint Tests

Pinpoint Test J: The In-Dash Computer Is Inoperative

Refer to Wiring Diagram Set 141, Ford Work Solutions for schematic and connector information. Diagrams By Number

Normal Operation

The in-dash computer receives power and ground from the vehicle harness. It also monitors information over the Medium Speed Controller Area Network (MS-CAN), and without this information, it does not power-up.

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- In-dash computer


PINPOINT TEST J: THE IN-DASH COMPUTER IS INOPERATIVE

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

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery, Mounting and Cables Battery Disconnect.

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J1 CHECK THE IN-DASH COMPUTER VOLTAGE SUPPLY


- Ignition OFF.
- Disconnect: In-Dash Computer .
- Measure the voltage between the in-dash computer C2408a-1, circuit (WH/RD), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to J2.

No
VERIFY the Central Junction Box (CJB) fuse 151 (15A) is OK. If OK, REPAIR the circuit. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number

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J2 CHECK THE IN-DASH COMPUTER GROUND CIRCUIT FOR CONTINUITY


- Measure the resistance between the in-dash computer C2408a-13, circuit (BK/BU), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to J3.

No
REPAIR the circuit. TEST the system for normal operation.

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J3 CHECK THE MS-CAN CIRCUIT INTEGRITY TO THE IN-DASH COMPUTER


- Disconnect: Negative Battery Cable .
- Measure the resistance between the in-dash computer C2408b-15, circuit (GY/OG), harness side and the Data Link Connector (DLC) C251-3, circuit 4-EC1 (GY/RD), harness side.




- Measure the resistance between the in-dash computer C2408b-16, circuit (VT/OG), harness side and the DLC C251-11, circuit 5-EC1 (BU/RD), harness side.




- Are the resistances less than 5 ohms?

Yes
GO to J4.

No
REPAIR the circuit in question for an open. TEST the system for normal operation.

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J4 CHECK FOR CORRECT IN-DASH COMPUTER OPERATION


- Disconnect all the in-dash computer connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the in-dash computer 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 in-dash computer. REFER to In-Dash Computer In-Dash Computer. 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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