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TEST ACTION APPLICABILITY
11 Ignition Off
Disconnect the Speed Control Servo 4-Way Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the resistance of the S/C Brake Switch Output Circuit
from the Servo Connector to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair shorted S/C Brake Switch Output Circuit.
Perform Verification TEST VER-4A
No®Go To 12
12 Ignition Off
Disconnect the Speed Control Servo 4-Way Connector.
Disconnect the Brake Switch Connector.
Note: Check connectors - Clean/repair as necessary.
With an Ohmmeter, measure the resistance of the S/C Brake Switch Output Circuit.
Is the resistance below 5.0 ohms?All
Ye s®Go To 13
No®Repair the open S/C Brake Switch Output.
Perform Powertrain Verification Test VER-4A
13 If there are no potential causes remaining, the Brake Switch is assumed to be
defective.
View repair options.All
Repair
Replace the Brake Switch.
Perform Powertrain Verification Test VER-4A.
14 Ignition Off
Disconnect the Brake Switch Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the resistance of the S/C Brake Switch Output Circuit
from the Brake Switch Connector to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair shorted S/C Brake Switch Output Circuit.
Perform Verification TEST VER-4A
No®Go To 15
15 Ignition off.
Disconnect the Powertrain Control Module.
Disconnect the Brake Switch Connector.
Note: Check connectors - Clean/repair as necessary.
With an ohmmeter, test resistance of the Speed Control Power Supply Ckt.
Is the resistance below 5.0 ohms?All
Ye s®Go To 16
No®Repair the open Speed Control Power Supply Circuit.
Perform Powertrain Verification Test VER-4A.
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P-1595 SPEED CONTROL SOLENOID CIRCUITS ÐContinued
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TEST ACTION APPLICABILITY
16 Ignition off.
If there are no potential causes remaining, the Powertrain Control Module is
assumed to be defective.
View repair options.All
Repair
Replace the Powertrain Control Module.
Perform Powertrain Verification Test VER-4A.
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P-1595 SPEED CONTROL SOLENOID CIRCUITS ÐContinued
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Symptom:
SPEED CONTROL BRAKE SWITCH OUTPUT
POSSIBLE CAUSES
GROUND CIRCUIT OPEN
PCM CONNECTOR OBSERVABLE DEFECT
BRAKE SWITCH DEFECTIVE
BRAKE SWITCH SENSE CIRCUIT OPEN
BRAKE SWITCH SENSE CIRCUIT SHORTED TO GROUND
PCM DEFECTIVE
TEST ACTION APPLICABILITY
1 Ignition Off
Disconnect the Brake Switch Connector.
Note: Check connectors - Clean/repair as necessary.
Key on.
Using a Voltmeter, measure the voltage of the Brake Switch Sense at the Brake
Switch Connector.
Is the voltage above 10 volts?All
Ye s®Go To 2
No®Go To 3
2 Ignition Off
Disconnect the Brake Switch Connector.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper between the Brake Switch Sense and Brake Switch Ground CKT.
With the DRB, read the Brake Switch input status.
Does the DRB show Brake SW9Released9?All
Ye s®Replace the Brake Switch.
Perform Powertrain Verification Test VER-4A
No®Repair the open Brake Switch Ground CKT.
Perform Powertrain Verification Test VER-4A.
3 Ignition Off
Disconnect the PCM.
Note: Check connectors - Clean/repair as necessary.
Is any Terminal damaged, pushed out or miswired?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-4A.
No®Go To 4
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TEST ACTION APPLICABILITY
4 Ignition Off
Disconnect the Brake Switch Connector.
Disconnect the PCM Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the Brake Switch Sense Circuit from Brake Switch to
PCM.
Is the resistance below 5.0 ohms?All
Ye s®Go To 5
No®Repair the open Brake Switch Sense Circuit.
Perform Powertrain Verification Test VER-4A.
5 Ignition Off
Disconnect the Brake Switch Connector.
Disconnect the PCM.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure resistance of Brake Switch Sense Circuit from the
Brake Switch Connector to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Brake Switch Sense Circuit, shorted to ground.
Perform Powertrain Verification Test VER-4A.
No®Go To 6
6 If there are no potential causes remaining, the PCM is assumed to be defective.
View repair options.All
Repair
Replace the PCM.
Perform Powertrain Verification Test VER-4A.
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SPEED CONTROL BRAKE SWITCH OUTPUT ÐContinued
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Symptom:
SPEED CONTROL DENIED MESSAGE
TEST ACTION APPLICABILITY
1 At this time the S/C switch and servo functions appear to operate properly.
Using the DRB, monitor the speed control9cutout9status.
Road test the vehicle at speeds over 30mph and attempt to set the speed control.
The following items will not allow the speed control to set. The last or most recent
cause for speed control not to set is indicated by the9Denied9status.
If ON/OFF Denied message is indicated, the Powertrain Control Module does not see
an9ON9signal from the switch at cavity 41.
If SPEED Denied message is indicated, the vehicle speed as seen by the Powertrain
Control Module at cavity 66 is not greater than 36 mph.
If RPM Denied message is indicated, the engine rpm is excessively high.
If BRAKE Denied message is indicated, the Brake Switch Sense Circuit is open
indicating to the PCM that the Brakes are applied. The Sense Circuit, cavity 62 of the
PCM, is grounded through the Brake Pedal Switch when the Brakes are released.
If P/N Denied message is indicated, Park/Neutral Switch Sense Circuit is grounded
indicating to PCM that transmission is not in gear. The Sense Circuit, cavity 76 of
PCM, is grounded through the Park/Neutral Switch when transmission is in park or
neutral.
If RPM/SPD Denied message is indicated, the PCM senses excessive engine rpm for
a given vehicle speed.
If SOL FLT Denied message is indicated, the Powertrain Control Module senses a
Servo Solenoid Circuit trouble code that is maturing or set in memory.All
Test Complete.
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Symptom:
SPEED CONTROL ON/OFF SWITCH
POSSIBLE CAUSES
CLOCKSPRING DEFECTIVE
PCM DEFECTIVE (SPEED CONTROL ON/OFF/SET SWITCH)
SPEED CONTROL GROUND CIRCUIT TO SWITCH OPEN
SPEED CONTROL ON/OFF SWITCH DEFECTIVE
SPEED CONTROL ON/OFF SWITCH SIGNAL CIRCUIT OPEN
SPEED CONTROL ON/OFF SWITCH SIGNAL CIRCUIT SHORT TO GROUND
SPEED CONTROL ON/OFF SWITCH TERMINAL DAMAGED
TEST ACTION APPLICABILITY
1 Ignition on, engine not running.
With the DRBIII, monitor the Speed Control Switch inputs.
While observing the display, press the Speed Control ªONº switch.
Does the DRBIII show S/C on/off ªONº?All
Ye s®Test Complete.
Perform Powertrain Verification Test VER-4A.
No®Go To 2
2 Ignition Off
Disconnect the Speed Control On/Off and Set Switch.
Note: Check connectors - Clean/repair as necessary.
Is any terminal damaged, pushed out or miswired?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-4A.
No®Go To 3
3 Ignition Off
Disconnect the Speed Control On/Off and Set Switch.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the resistance of the S/C Ground Circuit at the S/C
ON/OFF, SET Switch Connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 4
No®Repair the open Speed Control Ground Circuit to Switch.
Perform Powertrain Verification Test VER-4A.
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TEST ACTION APPLICABILITY
4 Ignition Off
Disconnect the Speed Control On/Off and Set Switch.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire across the S/C Sw Signal Circuit to Ground Circuit.
Ignition On, Engine Not Running.
With the DRBIII, read the S/C Switch voltage.
Does the DRBIII display 0.00 volts?All
Ye s®Replace the S/C ON/OFF and SET Switch.
Perform Powertrain Verification Test VER-4A.
No®Go To 5
5 Ignition Off
Disconnect the Speed Control On/Off and Set Switch.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the resistance of the S/C Switch Signal at the S/C
ON/OFF, SET Switch Connector to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Speed Control Switch Signal Circuit for a short to
ground.
Perform Powertrain Verification Test VER-4A.
No®Go To 6
6 Ignition Off
Disconnect the Powertrain Control Module.
Disconnect the Clockspring 4±way to I/P Harness.
Note: Check connectors - Clean/repair as necessary.
Using an ohmmeter, test the S/C Switch Signal Circuit, Clockspring to PCM.
Is the resistance below 5.0 ohms?All
Ye s®Go To 7
No®Repair the open Speed Control Switch Signal Circuit.
Perform Powertrain Verification Test VER-4A.
7 Ignition Off
Disconnect the Speed Control On/Off and set Switch.
Disconnect the Powertrain Control Module.
Note: Check connectors - Clean/repair as necessary.
Using an ohmmeter, measure the S/C Switch Signal Ckt, Switch to PCM.
Is the resistance below 5.0 ohms?All
Ye s®Replace the Powertrain Control Module.
Perform Powertrain Verification Test VER-4A.
No®Go To 8
8 If there are no potential causes remaining, the Clockspring is assumed to be
defective.
View repair options.All
Repair
Replace the Clockspring.
Perform Powertrain Verification Test VER-4A.
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SPEED CONTROL ON/OFF SWITCH ÐContinued
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Symptom:
* CHECKING SPEED CONTROL OPERATION
POSSIBLE CAUSES
BRAKE SWITCH DEFECTIVE
GROUND CIRCUIT OPEN
S/C BRAKE SWITCH OUTPUT CIRCUIT SHORTED TO GROUND
SPEED CONTROL BRAKE SWITCH OUTPUT SUPPLY CKT OPEN
SPEED CONTROL ON/OFF/SET SWITCH DEFECTIVE
SPEED CONTROL POWER SUPPLY CIRCUIT OPEN
SPEED CONTROL POWER SUPPLY CIRCUIT SHORTED/GROUND
SPEED CONTROL SERVO CONNECTOR OBSERVABLE DEFECT
SPEED CONTROL SWITCH DEFECTIVE
CLOCK SPRING DEFECTIVE
SPEED CONTROL SERVO DEFECTIVE
SPEED CONTROL THROTTLE CABLE DEFECTIVE
SPEED CONTROL VACUUM SUPPLY LEAKS OR RESTRICTED
PCM DEFECTIVE (SPEED CONTROL OPERATION)
VACUUM RESERVOIR DEFECTIVE
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
With the DRB, monitor the Speed Control Switch inputs.
While observing display, press the Speed Control ON/OFF switch.
Does the DRB show S/C ON/OFF switch9ON9?All
Ye s®Go To 2
No®Refer to symptom SPEED CONTROL ON/OFF SWITCH in the
SPEED CONTROL category.
2 Ignition On, Engine Not Running
Press the S/C ON/OFF button to select S/C ªON.º
With the DRB, monitor the Speed Control Switch inputs.
While observing the DRB, press the ACCEL/RESUME/CANCEL and DECEL
switches several times.
Do all of the Switches toggle correctly between pressed and released?All
Ye s®Go To 3
No®Go To 25
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