For 1990-2009 cars

### Circuit Description

The instrument panel cluster (IPC) diagnostic system check is an organized approach to identify problems associated with the module. This check must be the starting point for any module complaint. This check will direct you to the next logical step in diagnosing the complaint. The module is a very reliable component and is not likely the cause of the malfunction. Most system complaints are linked to faulty wiring and connectors, and occasionally to components. Understanding the computer system and using the tables correctly reduces diagnostic time and prevents unnecessary parts replacement.

### Diagnostic Aids

• | The following conditions may result in an intermittent operation of the module with no DTC stored:

- | Any condition which results in the interruption of power to the module

- | Out of range battery or ignition voltage

Specification
Normal module operating voltage: 9.0-15.5 V

- | A loose or damaged ground(s)

- | An open or shorted serial data line

• | An intermittent failure in the electronic system may be very difficult to detect and to accurately diagnose. The module tests for different malfunctions under different vehicle conditions. A thorough test drive is often needed in order to repeat a malfunction. If the system malfunction is not repeated during the test drive, a good description of the complaint may be very useful in locating an intermittent malfunction. Faulty electrical connections or wiring causes most intermitting problems. When an intermittent condition is suspected, test the suspected circuits for the following conditions:

- | Poor mating of connector halves or backed out terminals

- | Improperly formed or damaged terminals

- | Wire chafing

- | Poor wire-to-terminal connections

- | Dirty or corroded terminals

- | Damage to connector bodies

• | Use the J 35616 whenever a diagnostic procedure requests probing or testing a terminal. Using this adapter ensures that the terminal will not be damaged and will give an idea of whether the contact tension is sufficient.

• | If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur. Perform a thorough inspection of all of the related wiring and the connectors pertaining to the history DTC stored. Refer to Intermittents and Poor Connections Diagnosis .

• | Exit all scan tool tests before cycling the ignition from OFF to ON, unless the scan tool instructions direct otherwise. Follow the operating instructions in the scan tool operator's manual. Failure to follow these instruction may cause the following results:

- | The DTCs set.

- | The vehicle system malfunctions.

- | False DTCs set.

- | The scan tool malfunctions.

### Test Description

The numbers below refer to the step numbers on the diagnostic table:

1. This test determines if communication can be established with the module.

2. This test checks for stored module DTCs.

3. This test determines whether communication can be established with other modules connected to the Class 2 serial data line.

4. This test checks for any open module power fuses.

5. This test checks the module power circuit. If the test light does not turn on, there is an open in the module power circuit.

6. This test checks the module ground circuit. If the test light does not turn on, there is an open in the module power circuit.

#### IPC Diagnostic System Check

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 |

1. Turn the ignition switch OFF.
2. Connect a scan tool.
3. Turn the ignition switch ON.
4. Attempt to establish communication with the instrument panel cluster (IPC).

Does the scan tool communicate with the module?

--

Go to Step 2

Go to Step 3

2 | Select the display instrument cluster (IPC) DTC function with the scan tool. Are any current DTCs stored? | -- | Go to Diagnostic Trouble Code (DTC) List/Type | Go to Instrument Cluster System Check
3 | Are any history DTCs stored? | -- | Go to Step 4 | Go to Instrument Cluster System Check
4 | Clear the DTCs. Refer to Diagnostic System Check - Instrument Cluster . Are the history DTCs cleared? | -- | Go to Intermittents and Poor Connections Diagnosis | --
5 | Attempt to establish communications with the other modules connected to the same serial data line (PCM, RFA, HVAC, etc.). Does the scan tool communicate with the other modules? | -- | Go to Step 4 | Go to Data Link Communications System Check
6 |

1. Turn the ignition switch ON.
2. With a J 39200 connected to ground, probe each IPC fuse.

Does the displayed voltage measure near the specified value?

12.5 V

Go to Step 5

Go to Step 7

7 |

1. Turn the ignition switch OFF.
2. Disconnect the IPC connectors.
3. Turn the ignition switch ON.
4. With a J 39200 connected to ground, probe all of the module power circuits.

Does the displayed voltage measure near the specified value?

12.5 V

Go to Step 6

Go to Step 9

8 | With a J 39200 connected to ground, probe all of the IPC ground circuits. Does the voltage measure in the specified range? | 0.0-0.3 V | Go to Step 8 | Go to Step 10
9 |

1. Repair the open in the ignition or the battery feed to the IPC fuse.
2. If the fuse is open, test for a short to ground in the circuit connected to the open fuse.

Did you complete the repair?

--

Go to Step 1

--

10 | Replace the instrument cluster. Refer to IP Cluster Replacement. Did you complete the repair? | -- | Go to Step 1 | --
11 | Locate and repair the open in the IPC power circuit. Did you complete the repair? | -- | Go to Step 1 | --
12 | Locate and repair the open in the IPC ground circuit. Did you complete the repair? | -- | Go to Step 1 | --
13 |

1. Turn the ignition switch OFF.
2. Clear all of the DTCs. Refer to Clearing DTCs.

Are all of the DTCs cleared?

--

Go to Instrument Cluster System Check

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