For 1990-2009 cars

## Check Gages Indicator Inoperative L18 8.1L Gasoline Engine

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Instrument Cluster Schematics
1 | Did you perform the Instrument Panel Cluster Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Instrument Cluster
2 |

1. Turn the ignition ON, with the engine OFF.
2. Observe the CHECK GAGES indicator in the IPC.

Does the CHECK GAGES indicator illuminate during the displays test?

Go to Step 4

Go to Step 3

3 |

1. Turn the ignition OFF.
2. Disconnect C210.
3. Connect a 3 ampere fused jumper between the check gages indicator control circuit and a good ground.
4. Turn the ignition ON, with the engine OFF.

Does the CHECK GAGES indicator illuminate in the IPC?

Go to Step 5

Go to Step 6

4 | Test the check gages indicator control circuit for an open or for a high resistance between the multifunction alarm module (MFAM) and S244. 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 7
5 | Test the check gages indicator control circuit for an open or for a high resistance between C210 and the PCM. 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 9
6 | Test the check gages indicator control circuit for an open or for a high resistance between C210 and the IPC. 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 MFAM. 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 10
8 | 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
9 | Inspect for poor connections at the harness connector of the PCM. 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
10 | Replace the MFAM. Refer to Multifunction Alarm Module Replacement . Did you find and correct the condition? | 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 PCM. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 8.1L. 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 2

## Check Gages Indicator Inoperative 7.2L Diesel Engine LG5

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Instrument Cluster Schematics
1 | Did you perform the Instrument Panel Cluster Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Instrument Cluster
2 |

1. Turn the ignition ON, with the engine OFF.
2. Observe the CHECK GAGES indicator in the instrument panel cluster (IPC).

Does the CHECK GAGES indicator illuminate briefly during the displays test?

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

Go to Step 3

3 |

1. Turn the ignition OFF.
2. Disconnect the engine oil pressure (EOP) switch.
3. Connect a 3 ampere fused jumper between the signal circuit of the engine oil pressure sensor and a good ground.
4. Turn the ignition ON, with the engine OFF.
5. Observe the CHECK GAGES indicator in the IPC.

Does the CHECK GAGES indicator illuminate in the IPC?

Go to Step 11

Go to Step 4

4 | Test the engine oil pressure switch signal circuit for an open or for a high resistance between the multifunction alarm module (MFAM) and the EOP switch. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 5
5 |

1. Turn the ignition OFF.
2. Disconnect the engine coolant temperature (ECT) switch.
3. Connect a 3 ampere fused jumper between the signal circuit of the ECT switch and a good ground.
4. Turn the ignition ON, with the engine OFF.
5. Observe the CHECK GAGES indicator in the IPC.

Does the CHECK GAGES indicator illuminate in the IPC?

Go to Step 12

Go to Step 6

6 | Test the ECT switch signal circuit for an open or for a high resistance between the MFAM and the ECT switch. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 7
7 |

1. Turn the ignition OFF.
2. Disconnect the MFAM connector C1.
3. Connect a 3 ampere fused jumper between the check gages indicator control circuit and a good ground.
4. Turn the ignition ON, with the engine OFF.
5. Observe the CHECK GAGES indicator in the IPC.

Does the CHECK GAGES indicator illuminate in the IPC?

Go to Step 10

Go to Step 8

8 | Test the check gages indicator control circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 9
9 | 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 17 | Go to Step 15
10 | Inspect for poor connections at the harness connector of the MFAM. 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 17 | Go to Step 16
11 | Inspect for poor connections at the harness connector of the EOP switch. 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 17 | Go to Step 13
12 | Inspect for poor connections at the harness connector of the ECT switch. 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 17 | Go to Step 14
13 | Replace the EOP switch. Refer to the Cat® Medium Duty Diesel Manual - LG5. Did you complete the replacement? | Go to Step 17 | --
14 | Replace the ECT switch. Refer to the Cat® Medium Duty Diesel Manual - LG5. Did you complete the replacement? | Go to Step 17 | --
15 | Replace the IPC. Refer to Instrument Cluster Replacement . Did you complete the replacement? | Go to Step 17 | --
16 | Replace the MFAM. Refer to Multifunction Alarm Module Replacement . Did you complete the replacement? | Go to Step 17 | --
17 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2