For 1990-2009 cars

### Circuit Description

Internal defects in the cruise control module set DTC 55.

### Conditions for Setting the DTC

Cruise control module hardware failure (EEPROM defective).

### Conditions for Clearing the DTC

• | Replacing the module.

• | A history DTC will clear after 20 consecutive ignition cycles if the condition for the fault is no longer present.

### Diagnostic Aids

Check the integrity of the power and ground circuits before replacing the cruise control module.

### Test Description

The numbers below refer to numbers on the diagnostic table.

1. This step checks for proper voltage to the cruise control module.

2. This step checks for proper ground to the cruise control module.

#### DTC 55 Cruise Control Module Malfunction

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Cruise Control System Check performed? | -- | Go to Step 2 | Go to Cruise Control System Check
2 |

1. Disconnect the cruise control module connector.
2. Turn the ignition switch to the ON position.
3. Use the DMM to measure the voltage between terminal F of the cruise control module connector and a known good ground.

Is the measured voltage within the specified value?

B+

Go to Step 4

Go to Step 3

3 |

1. Locate an open or high resistance in circuit X500.
2. Repair the open or the high resistance in circuit X500.

Is the repair complete?

--

Go to Step 7

--

4 | Use the DMM to measure the resistance between terminal E of the cruise control module connector and a known good ground. Is the measured resistance within the specified value? | Less than 5 ohms | Go to Step 6 | Go to Step 5
5 |

1. Locate an open or high resistance in circuit F500.
2. Repair the open or the high resistance in circuit F500.

Is the repair complete?

--

Go to Step 7

--

6 | Replace the cruise control module. Is the replacement complete? | -- | Go to Step 7 | --
7 |

1. Connect all connectors and components that were disconnected.
2. Verify that the cruise control module operates properly and that there are no DTCs present.

Does the cruise control module operate properly?

--

System OK

Go to Cruise Control System Check