Important: A short to ground will cause an open fuse(s). Before performing this diagnostic procedure, inspect the fuse(s) for an open.

1. Remove the scan tool from the data link connector (DLC).
2. Measure the voltage between terminal 16 of the DLC and ground.

Is the voltage measured to the specified value?

B+

Go to Step 2

Go to Step 3

Measure the voltage between terminal 5 and terminal 16 of the DLC.

Is the voltage measured to the specified value?

B+

Go to Step 4

Go to Step 5

Repair the open in CKT 40 between the fuse block and the DLC. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Data Link Communications System Check

--

Measure the voltage between terminal 4 and terminal 16 of the DLC.

Is the voltage measured to the specified value?

B+

Go to Step 6

Go to Step 7

Repair the open in CKT 451 between the DLC and G110. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Data Link Communications System Check

--

1. Reconnect the scan tool to the DLC.
2. Attempt to establish communication with each module connected to the DLC.

Can communication be established with each module?

--

Go to Data Link Communications System Check

Go to Step 8

Repair the open in CKT 150 between the DLC and G204. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Data Link Communications System Check

--

Refer to the appropriate diagnostic table within this section.

Is the repair complete?

--

Go to Data Link Communications System Check

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