For 1990-2009 cars

Refer to Engine Controls Schematics .

### Circuit Description

Output driver modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the device which the PCM is commanding ON. DTC P1585 set indicates an improper voltage level has been detected on the output circuit which controls the Cruise Control Inhibit circuit.

### Conditions for Running the DTC

• | The ignition is ON.

• | The system voltage between 9.0 and 18.0 volts.

### Conditions for Setting the DTC

• | An improper voltage level has been detected on the output circuit which controls the cruise control inhibit.

• | The above condition is present for at least 30 seconds.

### Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

### Conditions for Clearing the MIL/DTC

• | The DTC becomes history when the conditions for setting the DTC are no longer present.

• | The history DTC clears after 40 malfunction free warm-up cycles.

• | The PCM receives a clear code command from the scan tool.

### Diagnostic Aids

Inspect for the following conditions:

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

• | Loose terminal connection

- | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.

- | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.

• | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

• | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

### Test Description

Numbers below refer to the step numbers on the Diagnostic Table.

1. Normally, ignition feed voltage should be present on the control circuit with the PCM disconnected and the ignition turned ON.

2. Tests for a shorted component or a short to battery positive voltage on the control circuit. Either condition would result in a measured current of over 500 milliamps. Also tests for a component that is going open while being operated, resulting in a measured current of 0 milliamps.

3. Tests for a short to voltage on the control circuit.

4. This vehicle is equipped with a PCM which utilizes an electrically erasable programmable read only memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.

#### DTC P1585 -- Cruise Control Inhibit Control Circuit

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 |

1. Turn OFF the ignition switch.
2. Disconnect the PCM.
3. Turn ON the ignition switch.
4. Using a DMM, measure voltage between the Cruise Control Module control circuit at the PCM harness connector and ground.

Is voltage near the specified value?

B+

Go to Step 3

Go to Step 6

3 |

1. Connect the DMM to measure current between the cruise inhibit control circuit at the PCM harness connector and ground.
2. Monitor the current reading on the DMM for at least 2 minutes.

Does the current reading remain between the specified values?

0.001-0.5 amp

(1-500 mA)

Go to Step 11

Go to Step 4

4 |

1. Turn OFF the ignition switch.
2. Disconnect the stepper motor cruise control module (leave the PCM disconnected).
3. Turn ON the ignition switch.
4. Using the digital multimeter, measure voltage between the cruise inhibit control circuit and ground.

Is voltage at the specified value?

0 V

Go to Step 10

Go to Step 5

5 | Locate and repair short to voltage in the cruise inhibit control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 16 | --
6 |

1. Turn OFF the ignition switch.
2. Test the ignition feed fuse for the Cruise Control Module.

Is the fuse open?

--

Go to Step 7

Go to Step 8

7 |

1. Locate and repair short to ground in ignition feed circuit for the Cruise Control Module. Refer to Wiring Repairs in Wiring Systems.
2. Replace the fuse.

Did you complete the repair?

--

Go to Step 16

--

8 |

1. Disconnect the Cruise Control Module.
2. Turn ON the ignition switch.
3. Measure voltage between the ignition feed circuit for the Cruise Control Module and ground.

Is voltage near the specified value?

B+

Go to Step 9

Go to Step 13

9 | Test the cruise inhibit control circuit for an open or a short to ground. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 10
10 |

1. Test for the following conditions:

• | The cruise inhibit control circuit for a poor connection at the PCM.

• | The cruise inhibit control circuit for a poor connection at Cruise Control Module.

• | The Cruise Control Module ignition feed circuit for a poor connection at the Cruise Control Module.

2. If a problem is found, replace loose terminals as necessary. Refer to Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 16

Go to Step 14

11 |

1. Turn OFF the ignition switch.
2. Reconnect the PCM.
3. Disconnect the Cruise Control Module.
4. Turn ON the ignition switch.
5. Connect a test lamp between the cruise inhibit control circuit and the ignition feed circuit at the Cruise Control Module harness connector.
6. Using the scan tool outputs test function, cycle the cruise inhibit output ON and OFF.

Does the test lamp flash ON and OFF?

--

Go to Diagnostic Aids

Go to Step 12

12 | Test the cruise inhibit control circuit for a poor connection at the PCM. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 15
13 | Locate and repair open in ignition feed circuit to the Cruise Control Module. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 16 | --
14 | Replace the Cruise Control Module. Refer to Cruise Control Module Replacement in Cruise Control. Did you complete the replacement? | -- | Go to Step 16 | --
15 | Important: : The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | Go to Step 16 | --
16 |

1. Review and record scan tool Fail Records data.
2. Clear DTCs.
3. Operate the vehicle within Fail Records conditions.
4. Using a scan tool, monitor Specific DTC info for DTC P1585 until the DTC P1585 test runs.

Does the scan tool indicate DTC P1585 failed this ignition?

--

Go to Step 2

System OK