DTC P0579:00 [L5]

DTC P0579:00	Cruise control multi-function input circuit range/performance problem
DETECTION CONDITION	• The PCM monitors the input signal from the cruise control switch. If the input signal does not change for 120 s, the PCM determines that the cruise control switch circuit has a malfunction. Diagnostic support note • This is a continuous monitor (other). • The MIL does not illuminate. • FREEZE FRAME DATA (Mode 2)/Snapshot data is not available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• Clock spring connector or terminals malfunction • Clock spring malfunction • Cruise control switch malfunction • Short to ground in wiring harness between clock spring terminal 2L and PCM terminal 1AQ • PCM connector or terminals malfunction • Short to power supply in wiring harness between the following terminals: ― Clock spring terminal 2L—PCM terminal 1AQ ― Clock spring terminal 2N—PCM terminal 1AN • Open circuit in wiring harness between the following terminals: ― Clock spring terminal 2L—PCM terminal 1AQ ― Clock spring terminal 2N—PCM terminal 1AN • PCM malfunction

DTC P0579:00

Cruise control multi-function input circuit range/performance problem

DETECTION CONDITION

• The PCM monitors the input signal from the cruise control switch. If the input signal does not change for 120 s, the PCM determines that the cruise control switch circuit has a malfunction.

Diagnostic support note

• This is a continuous monitor (other).

• The MIL does not illuminate.

• FREEZE FRAME DATA (Mode 2)/Snapshot data is not available.

• The DTC is stored in the PCM memory.

POSSIBLE CAUSE

• Clock spring connector or terminals malfunction

• Clock spring malfunction

• Cruise control switch malfunction

• Short to ground in wiring harness between clock spring terminal 2L and PCM terminal 1AQ

• PCM connector or terminals malfunction

• Short to power supply in wiring harness between the following terminals:

― Clock spring terminal 2L—PCM terminal 1AQ

― Clock spring terminal 2N—PCM terminal 1AN

• Open circuit in wiring harness between the following terminals:

― Clock spring terminal 2L—PCM terminal 1AQ

― Clock spring terminal 2N—PCM terminal 1AN

• PCM malfunction

STEP	INSPECTION	ACTION
1	VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to the next step.
No	Go to the next step.
2	INSPECT CLOCK SPRING CONNECTOR CONDITION Warning • Handling the air bag system components improperly can accidentally deploy the air bag modules and pre-tensioner seat belts, which may seriously injure you. Read the air bag system service warnings and cautions before handling the air bag system components. (See AIR BAG SYSTEM SERVICE WARNINGS.) (See AIR BAG SYSTEM SERVICE CAUTIONS.) • Turn the ignition switch off. • Disconnect the clock spring connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 9.
No	Go to the next step.
3	INSPECT CLOCK SPRING • Inspect the clock spring. (See CLOCK SPRING INSPECTION.) • Is there any malfunction?	Yes	Replace the clock spring, then go to Step 9. (See CLOCK SPRING REMOVAL/INSTALLATION.)
No	Go to the next step.
4	INSPECT CRUISE CONTROL SWITCH • Inspect the cruise control switch. (See CRUISE CONTROL SWITCH INSPECTION [L5].) • Is there any malfunction?	Yes	Replace the steering switch, then go to Step 9. (See STEERING SWITCH REMOVAL/INSTALLATION.)
No	Go to the next step.
5	INSPECT CRUISE CONTROL SWITCH CIRCUIT FOR SHORT TO GROUND • Clock spring connector is disconnected. • Inspect for continuity between clock spring terminal 2L (wiring harness-side) and body ground. • Is there continuity?	Yes	If the short to ground circuit could be detected: • Repair or replace the wiring harness for a possible short to ground. If the short to ground circuit could not be detected: • Replace the PCM (short to ground in PCM internal circuit). (See PCM REMOVAL/INSTALLATION [L5].) Go to Step 9.
No	Go to the next step.
6	INSPECT PCM CONNECTOR CONDITION • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 9.
No	Go to the next step.
7	INSPECT CRUISE CONTROL SWITCH CIRCUIT FOR SHORT TO POWER SUPPLY • Clock spring and PCM connectors are disconnected. • Turn the ignition switch to the ON position (engine off). • Measure the voltage at the following terminals (wiring harness-side): ― Clock spring terminal 2L ― Clock spring terminal 2N • Is there any voltage?	Yes	Repair or replace the wiring harness for a possible short to power supply, then go to Step 9.
No	Go to the next step.
8	INSPECT CRUISE CONTROL SWITCH CIRCUIT FOR OPEN CIRCUIT • Clock spring and PCM connectors are disconnected. • Turn the ignition switch off. • Inspect for continuity between the following terminals (wiring harness-side): ― Clock spring terminal 2L—PCM terminal 1AQ ― Clock spring terminal 2N—PCM terminal 1AN • Is there continuity?	Yes	Go to the next step.
No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9	VERIFY DTC TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [L5].) • Drive the vehicle using cruise control for 2 min or more. • Perform the DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [L5].) • Is the same DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [L5].)
No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [L5].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [L5].)
No	DTC troubleshooting completed.

STEP

INSPECTION

ACTION

VERIFY RELATED SERVICE INFORMATION AVAILABILITY

• Verify related Service Information availability.

• Is any related Service Information available?

Yes

Perform repair or diagnosis according to the available Service Information.

• If the vehicle is not repaired, go to the next step.

Go to the next step.

INSPECT CLOCK SPRING CONNECTOR CONDITION

Warning

• Handling the air bag system components improperly can accidentally deploy the air bag modules and pre-tensioner seat belts, which may seriously injure you. Read the air bag system service warnings and cautions before handling the air bag system components. (See AIR BAG SYSTEM SERVICE WARNINGS.) (See AIR BAG SYSTEM SERVICE CAUTIONS.)

• Turn the ignition switch off.

• Disconnect the clock spring connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 9.

Go to the next step.

INSPECT CLOCK SPRING

• Inspect the clock spring. (See CLOCK SPRING INSPECTION.)

• Is there any malfunction?

Yes

Replace the clock spring, then go to Step 9.

(See CLOCK SPRING REMOVAL/INSTALLATION.)

Go to the next step.

INSPECT CRUISE CONTROL SWITCH

• Inspect the cruise control switch. (See CRUISE CONTROL SWITCH INSPECTION [L5].)

• Is there any malfunction?

Yes

Replace the steering switch, then go to Step 9.

(See STEERING SWITCH REMOVAL/INSTALLATION.)

Go to the next step.

INSPECT CRUISE CONTROL SWITCH CIRCUIT FOR SHORT TO GROUND

• Clock spring connector is disconnected.

• Inspect for continuity between clock spring terminal 2L (wiring harness-side) and body ground.

• Is there continuity?

Yes

If the short to ground circuit could be detected:

• Repair or replace the wiring harness for a possible short to ground.

If the short to ground circuit could not be detected:

• Replace the PCM (short to ground in PCM internal circuit). (See PCM REMOVAL/INSTALLATION [L5].)

Go to Step 9.

Go to the next step.

INSPECT PCM CONNECTOR CONDITION

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 9.

Go to the next step.

INSPECT CRUISE CONTROL SWITCH CIRCUIT FOR SHORT TO POWER SUPPLY

• Clock spring and PCM connectors are disconnected.

• Turn the ignition switch to the ON position (engine off).

• Measure the voltage at the following terminals (wiring harness-side):

― Clock spring terminal 2L

― Clock spring terminal 2N

• Is there any voltage?

Yes

Repair or replace the wiring harness for a possible short to power supply, then go to Step 9.

Go to the next step.

INSPECT CRUISE CONTROL SWITCH CIRCUIT FOR OPEN CIRCUIT

• Clock spring and PCM connectors are disconnected.

• Turn the ignition switch off.

• Inspect for continuity between the following terminals (wiring harness-side):

― Clock spring terminal 2L—PCM terminal 1AQ

― Clock spring terminal 2N—PCM terminal 1AN

• Is there continuity?

Yes

Go to the next step.

Repair or replace the wiring harness for a possible open circuit, then go to the next step.

VERIFY DTC TROUBLESHOOTING COMPLETED

• Make sure to reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [L5].)

• Drive the vehicle using cruise control for 2 min or more.

• Perform the DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [L5].)

• Is the same DTC present?

Yes

Replace the PCM, then go to the next step.

(See PCM REMOVAL/INSTALLATION [L5].)

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

• Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [L5].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [L5].)

DTC troubleshooting completed.