Jeep XJ. Manual - part 861

TEST

ACTION

APPLICABILITY

Turn the ignition off.
Remove the A/C Clutch Relay.
Note: Check connectors - Clean/repair as necessary.
Measure the Fused B(+) at the Relay.
Is the voltage above 11.0 volts?

All

Yes

→

Go To

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Repair the open Fused B(+) Circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.

If there are no possible causes remaining, view repair.

All

Repair

Repair the open A/C Request Circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.

205

HEATING & A/C

*CHECKING A/C SYSTEM OPERATION WITH NO DTC’S —

Continued

Symptom List:

P1595-SPEED CONTROL SOLENOID CIRCUITS
P1683-SPD CTRL PWR RELAY; OR S/C 12V DRIVER CKT

Test Note:

All symptoms listed above are diagnosed using the same tests.

The title for the tests will be P1595-SPEED CONTROL SOLE-
NOID CIRCUITS.

When Monitored and Set Condition:

P1595-SPEED CONTROL SOLENOID CIRCUITS

When Monitored:

With the ignition key on, the speed control switched on, the SET switch

pressed and the vehicle in drive gear moving above 35 MPH.

Set Condition:

The powertrain control module actuates the vacuum and vent solenoids

but they do not respond.

P1683-SPD CTRL PWR RELAY; OR S/C 12V DRIVER CKT

When Monitored:

With the ignition key on and the speed control switched on.

Set Condition:

The speed control power supply circuit is either open or shorted to ground.

POSSIBLE CAUSES

S/C POWER SUPPLY CIRCUIT SHORTED TO GROUND

GROUND CIRCUIT AT S/C SERVO CONNECTOR OPEN

S/C WIRING HARNESS INTERMITTENT PROBLEM (S/C VENT SOL AC)

S/C VACUUM SOLENOID CONTROL CIRCUIT OPEN

S/C VACUUM SOLENOID CONTROL CKT SHORT TO GROUND

S/C VENT SOLENOID CONTROL CIRCUIT OPEN

S/C VENT SOLENOID CONTROL CKT SHORT TO GROUND

S/C WIRING HARNESS INTERMITTENT PROBLEM (S/C VAC SOL AC)

S/C WIRING HARNESS OBSERVABLE PROBLEM

S/C SERVO (12V DRIVER CIRCUIT)

S/C POWER SUPPLY CIRCUIT OPEN

BRAKE SWITCH

BRAKE SWITCH OUT OF ADJUSTMENT

S/C BRAKE SWITCH OUTPUT CIRCUIT OPEN

S/C BRAKE SWITCH OUTPUT CIRCUIT SHORTED TO GROUND

PCM (12V DRIVER CIRCUIT)

206

SPEED CONTROL

TEST

ACTION

APPLICABILITY

Ignition On, Engine Not Running.
With the DRBIII

t actuate the S/C Vent Solenoid.

Does the Speed Control Servo click?

All

Yes

→

Go To

→

Go To

Turn the ignition on.
With the DRBIII

t, actuate the S/C Vacuum Solenoid.

Does the Speed Control Servo click?

All

Yes

→

Go To

→

Go To

Turn the ignition off.
Using the Schematics as a guide, inspect the Wiring and Connectors.
Were any problems found?

All

Yes

→

Repair as necessary.
Perform POWERTRAIN VERIFICATION TEST VER - 4.

→

Go To

Turn the ignition on.
With the DRBIII

t, actuate the S/C Vent Solenoid..

Wiggle the Wiring Harness from S/C Servo and Brake Switch to Powertrain Control
Module.
Did the wiggling interrupt the S/C Servo actuation?

All

Yes

→

Repair as necessary where wiggling caused the actuation to be
interrupted.
Perform POWERTRAIN VERIFICATION TEST VER - 4.

→

Go To

Turn the ignition on.
With the DRBIII

t, actuate the S/C Vacuum Solenoid.

Wiggle the Wiring Harness from S/C Servo and Brake Switch to Powertrain Control
Module.
Did the wiggling interrupt the S/C actuation?

All

Yes

→

Repair as necessary where wiggling caused the actuation to be
interrupted.
Perform POWERTRAIN VERIFICATION TEST VER - 4.

→

Test Complete.

Turn the ignition on.
With the DRBIII

t, actuate the S/C Vent Solenoid..

Wiggle the Wiring Harness from S/C Servo and Brake Switch to Powertrain Control
Module.
Did the wiggling interrupt the S/C Servo actuation?

All

Yes

→

Repair as necessary where wiggling caused the actuation to be
interrupted.
Perform POWERTRAIN VERIFICATION TEST VER - 4.

→

Go To

207

SPEED CONTROL

P1595-SPEED CONTROL SOLENOID CIRCUITS —

Continued

TEST

ACTION

APPLICABILITY

Turn the ignition off.
Disconnect the Speed Control Servo harness connector.
Note: Check connectors - Clean/repair as necessary.
Note: Ensure the Brake Pedal is not depressed during the following steps.
Turn the ignition on.
Turn S/C Switch on.
With the DRBIII

t, actuate the S/C Vacuum Solenoid.

Using a 12-volt Test Light, check the S/C Brake Switch Output Circuit at the Servo
harness connector.
Is the light illuminated and bright?

All

Yes

→

Go To

→

Go To

Turn the ignition off.
Disconnect the Speed Control Servo harness connector.
Note: Check connectors - Clean/repair as necessary.
Measure the resistance of the Ground Circuit at the Servo harness connector to
ground.
Is the resistance below 5.0 ohms?

All

Yes

→

Go To

→

Repair open Ground Circuit at S/C Servo Connector.
Perform POWERTRAIN VERIFICATION TEST VER - 4.

Turn the ignition off.
Disconnect the Speed Control Servo 4-way harness connector.
Note: Check connectors - Clean/repair as necessary.
Note: Ensure the Brake Pedal is not depressed during the following steps.
Turn the ignition on.
Turn the S/C Switch on.
With the DRBIII

t, actuate the S/C Vacuum Solenoid.

Using a 12-volt Test Light, check the S/C Brake Switch Output Circuit at the Servo
harness connector.
Is the light illuminated and bright?

All

Yes

→

Go To

→

Go To

Turn ignition off.
Using Service Procedure, check Brake Switch adjustment.
Was Brake Switch adjustment OK?

All

Yes

→