Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics | ||||
1 | Did you review the system operation and perform the necessary inspections? | -- | Go to Step 2 | |
2 |
Does the Engine Speed parameter match the tachometer display? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 |
Does the voltage measure greater than the specified value? | 9.0 V | Go to Step 4 | Go to Step 9 |
4 | Measure the voltage from the tachometer ignition voltage circuit to the tachometer ground circuit. Does the voltage measure greater than the specified value? | 9.0 V | Go to Step 5 | Go to Step 10 |
5 |
Does the voltage measure greater than the specified value? | 9.0 V | Go to Step 7 | Go to Step 6 |
6 | Test the engine speed signal circuit for an open, for a short to ground or for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 8 |
7 | Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 |
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? | -- | Go to Step 13 | Go to Step 12 |
9 | Repair the open or the high resistance in the tachometer ignition voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 13 | -- |
10 | Repair the open or the high resistance in the tachometer ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repairs? | -- | Go to Step 13 | -- |
11 | Replace the IPC. Refer to Instrument Cluster Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
12 |
Important: Program the replacement ECM. Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data in Engine Controls - 7.8L. Did you complete the replacement? | -- | Go to Step 13 | -- |
13 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 3 |
