Tachometer Inaccurate or Inoperative

Step	Action	Value(s)	Yes	No
Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Engine Control Module Connector End Views for the 3.6L engine, Engine Control Module Connector End Views for the 4.4L engine, Engine Control Module Connector End Views for the 4.6L engine or Inline Harness Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Install a scan tool. Start the engine. With the scan tool, observe the Engine Speed parameter in the ECM Engine Data 1 data list. Does the Engine Speed parameter match the tachometer display?	-	Go to Testing for Intermittent Conditions and Poor Connections	Go to Step 3
3	Turn the ignition OFF. Disconnect the engine control module (ECM) connector C2. Turn the ignition ON, with the engine OFF. 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
4	Test the engine speed signal circuit for an open, for a high resistance, or for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 10	Go to Step 6
5	Test the engine speed signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 10	Go to Step 7
6	Inspect for poor connections at the harness connector of the instrument panel cluster (IPC). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 10	Go to Step 8
7	Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 10	Go to Step 9
8	Replace the IPC. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?	-	Go to Step 10	-
9	Replace the ECM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?	-	Go to Step 10	-
10	Operate the system in order to verify the repair. Did you correct the condition?	-	System OK	Go to Step 2