1. Turn OFF the ignition switch.
2. Install a scan tool.
3. Turn ON the ignition switch.
4. Attempt to establish communication with the following modules:

•	Dash integration module (DIM)

•	Instrument panel integration module (IPM)

•	Rear integration module (RIM)

Does the scan tool communicate with the modules?

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Go to Step 2

Go to Step 4

Select display module DTC function with the scan tool.

Are any DTCs stored?

--

Go to Step 3

System OK

Are any Loss of Class 2 Serial Data Communication DTCs set? (Loss of Class 2 Serial Data Communication DTCs have the form UXXXX.)

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Go to Diagnostic Trouble Code (DTC) List in Data Link Communications

Go to Diagnostic Trouble Code (DTC) List/Type

Attempt to establish communications with the other modules connected to the serial data line (PCM, IPC, etc.).

Does the scan tool communicate with the other modules?

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Go to Step 5

Go to Scan Tool Does Not Communicate with Class 2 Data Line in Data Link Communications

Test the module circuits for an open or short to ground.

Was an open or short found?

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Go to Step 8

Go to Step 6

1. Turn OFF the ignition switch.
2. Disconnect the module connectors.
3. Turn ON the ignition switch.
4. With a test light connected to ground, probe all module power circuits.

Does the test light turn on in all circuits?

--

Go to Step 7

Go to Step 9

Locate and repair the open in the module ground circuit.

Is the repair complete?

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Go to Step 10

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Locate and repair the open in the module power circuit.

Is the repair complete?

--

Go to Step 10

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Replace the module. Refer to one of the following:

Is the repair complete?

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Go to Step 10

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1. Turn OFF the ignition switch.
2. Connect or install any connectors or components that were disconnected or removed.
3. Clear all DTCs. Refer to Clearing DTCs.

Are all DTCs cleared?

System OK