Schematic Reference: Instrument Cluster Schematics

Connector End View Reference: Engine Control Module Connector End Views

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

1. Install a scan tool.
2. Start the engine.
3. With the scan tool, observe the Engine Speed parameter in the engine control module (ECM) Engine Data 1 data list.

Does the Engine Speed parameter match the tachometer display?

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Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

1. Turn OFF the ignition.
2. Disconnect the ECM connector C1.
3. Turn ON the ignition, with the engine OFF.
4. Measure the voltage from the engine speed signal circuit to a good ground.

Does the voltage measure greater than the specified value?

9 V

Go to Step 5

Go to Step 4

Test the engine speed signal circuit for the following:

Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 10

Go to Step 6

Test the engine speed signal circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 10

Go to Step 7

Inspect for poor connections at the harness connector of the instrument panel cluster (IPC). Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 10

Go to Step 8

Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 10

Go to Step 9

Replace the IPC. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

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Go to Step 10

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Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

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Go to Step 10

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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2