Pinpoint Test V: No Power to the Scan Tool

Communications Network

Pinpoint Tests

Pinpoint Test V: No Power To The Scan Tool

Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. Diagrams By Number

Normal Operation

The scan tool is connected to the Data Link Connector (DLC) to communicate with the High Speed Controller Area Network (HS-CAN) and the Medium Speed Controller Area Network (MS-CAN) communications network. Voltage for the scan tool is provided by circuit SBP11 (BU/RD). Ground is provided by both circuits GD116 (BK/VT).

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- Scan tool



PINPOINT TEST V: NO POWER TO THE SCAN TOOL

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.

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V1 CHECK THE DLC PINS FOR DAMAGE


NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test.

- Disconnect the scan tool cable from the DLC.
- Inspect DLC pins 4, 5 and 16 for damage.




- Are DLC pins 4, 5 and 16 OK?

Yes
GO to V2.

No
REPAIR the DLC as necessary. CLEAR the DTCs. REPEAT the network test with the scan tool.

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V2 CHECK THE DLC VOLTAGE SUPPLY FOR AN OPEN


- Measure the voltage between the DLC C251-16, circuit SBP11 (BU/RD), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to V3.

No
VERIFY the Smart Junction Box (SJB) fuse 18 (20A) is OK. If OK, REPAIR the circuit. REPEAT the network test with the scan tool.

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V3 CHECK THE DLC GROUND CIRCUITS FOR AN OPEN


- Disconnect: Negative Battery Cable.
- Measure the resistance between the DLC C251-4, circuit GD116 (BK/VT), harness side and ground; and between the DLC C251-5, circuit GD116 (BK/VT), harness side and ground.




- Are the resistances less than 5 ohms?

Yes
CONNECT the negative battery cable. REPAIR the scan tool. REPEAT the network test with the scan tool.

No
CONNECT the negative battery cable. REPAIR the circuit in question. REPEAT the network test with the scan tool.

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