DTC P1585 Cruise Control Inhibit Output Circuit. Chevrolet Malibu 1999

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 1999 🢒 Malibu 🢒 Engine 🢒 Engine Controls - 3.1L (LG8) 🢒 DTC P1585 Cruise Control Inhibit Output Circuit

Engine Controls Components
Cell 20: Cruise, VSS
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

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 stepper motor cruise control inhibit circuit.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

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

•	The above conditions present for at least 30 seconds.

Action Taken When the DTC Sets

•	The PCM will not illuminate the malfunction indicator lamp (MIL).

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

Conditions for Clearing the MIL/DTC

•	A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

•	The DTC can be cleared by using the scan tool Clear Info function.

Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Check for the following conditions:

•	Poor connection or damaged harness.

Inspect the vehicle wiring harness for an open or short to ground in the serial data circuit, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.

•	Intermittent test.

Observe ABS data on the scan tool while moving harness and related connectors. Refer to Data Line in Electrical Diagnosis for a complete mechanization of the serial data circuit and devices using the serial data line. If the failure is induced, the scan tool data will stop updating. This may help to isolate the location of the malfunction.

•	If the above items have been checked and no problem is found but DTC P1585 continues to set, replace the PCM.

Refer to Testing for Continuity , Intermittents and Poor Connections Diagnosis , Repairing Connector Terminals , and Connector Repairs in Wiring Systems.

Reviewing the Fail Records vehicle mileage after the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table:

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

Checks for a shorted component or a short to B+ on the control circuit. Either condition would result in a measured current of over 500 milliamps. Also checks for a component that is going open while being operated, resulting in a measured current of 0 milliamps.

Checks for a short to voltage on the control circuit.

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.

Step

Action

Value(s)

Yes

Was the Powertrain on-Board Diagnostic (OBD) System Check performed?

Go to Step 2

Go to the Powertrain On Board Diagnostic (OBD) System Check

Turn off the ignition switch.
Disconnect the PCM.
Turn on the ignition switch.
Using a J 39200 DMM, measure voltage between the stepper motor 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

Connect the J 39200 DMM to measure current between the cruise inhibit control circuit at the PCM harness connector and ground.
Monitor the current reading on the J 39200 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

Turn off the ignition switch.
Disconnect the stepper motor cruise control module (leave the PCM disconnected).
Turn on the ignition switch.
Using the J 39200 DMM, measure voltage between the cruise inhibit control circuit and ground.

Is voltage at the specified value?

0.0V

Go to Step 10

Go to Step 5

Locate and repair short to voltage in the cruise inhibit control circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 16

Turn off the ignition switch.
Check the ignition feed fuse for the stepper motor cruise control module.

Is the fuse blown?

Go to Step 7

Go to Step 8

Locate and repair short to ground in ignition feed circuit for the stepper motor cruise control module. Refer to Wiring Repairs in Wiring Systems.
Replace the fuse.

Is the action complete?

Go to Step 16

Disconnect the stepper motor cruise control module.
Turn on the ignition switch.
Using J 39200 DMM measure voltage between the ignition feed circuit for the stepper motor cruise control module and ground.

Is voltage near the specified value?

B+

Go to Step 9

Go to Step 13

Test the cruise inhibit control circuit for an open or a short to ground.
If a problem is found, repair the cruise inhibit control circuit. Refer to Wiring Repairs in Wiring Systems.

Was a problem found?

Go to Step 16

Go to Step 10

Inspect 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 stepper motor cruise control module.

•	The stepper motor cruise control module ignition feed circuit for a poor connection at the stepper motor cruise control module.

If a problem is found, replace loose terminal(s) as necessary. Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs in Wiring Systems.

Was a problem found?

Go to Step 16

Go to Step 14

Turn off the ignition switch.
Reconnect the PCM.
Disconnect the stepper motor cruise control module.
Turn on the ignition switch.
Connect a J 35616-200 test lamp between the cruise inhibit control circuit and the ignition feed circuit at the stepper motor cruise control module harness connector.
Using the scan tool outputs test function, cycle the cruise inhibit output on and off.

Does the J 35616-200 test lamp flash on and off?

Go to Diagnostic Aids

Go to Step 12

Test the cruise inhibit control circuit for a poor connection at the PCM.
If a problem is found, replace loose terminal. Refer to Testing for Continuity , Intermittents and Poor Connections Diagnosis , Repairing Connector Terminals , and Connector Repairs in Wiring Systems.

Was a problem found?

Go to Step 16

Go to Step 15

Locate and repair open in ignition feed circuit to the stepper motor cruise control module. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 16

Replace theCcruise Control Module. Refer to Cruise Control Module Replacement .

Is the action complete?

Go to Step 16

Important: : The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

Go to Step 16

Review and record scan tool Fail Records data.
Clear DTCs.
Operate the vehicle within Fail Records conditions.
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