Start by running speed control servo integrated self test diagnostics. The servo has integrated self test diagnostics which is a key tool in quickly and accurately diagnosing speed control system faults. Self test diagnostics are also the basis for starting speed control trouble shooting.
WARNING THIS TEST IS A KEY ON ENGINE OFF (KOEO) TEST THAT IS CONDUCTED ONLY WHILE PARKED WITH THE PARKING BRAKE FULLY ENGAGED. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
NOTE THIS SELF-TEST IS COMPRISED OF TWO PARTS. THE FIRST PART IS A STATIC CHECK OF THE SPEED CONTROL ELECTRONICS MODULE AND SYSTEM. THE SECOND PART IS A DYNAMIC PULL-TEST TO CHECK THE ACTUATOR MOTOR AND GEAR MECHANISM.
NOTE THE MODULE TIMES OUT IF EACH BUTTON IS NOT PRESSED WITHIN 1 SECOND OF THE PREVIOUS BUTTON. IF A MODULE TIME OUT OCCURS (SPEED CONTROL LAMP STOPS FLASHING PART WAY THROUGH THE TEST), THE PROCEDURE MUST BE RE-INITIATED.
NOTE ON VEHICLES EQUIPPED WITH A MANUAL TRANSMISSION, THE CLUTCH PEDAL SHOULD NOT BE DEPRESSED EXCEPT FOR ESCAPE/MARINER, WHICH SHOULD BE DEPRESSED, IN ORDER TO CORRECTLY PERFORM THE SELF-TEST. ON VEHICLES EQUIPPED WITH AN AUTOMATIC TRANSMISSION, THE TRANSMISSION SELECTOR LEVER NEEDS TO BE IN THE "P" POSITION FOR THE SELF TEST EXCEPT FOR THE ESCAPE/MARINER WHICH SHOULD BE IN "N".
NOTE REVIEW THE FOLLOWING STEPS BEFORE CARRYING OUT THE SELF-TEST DIAGNOSTIC PROCEDURE.
Self Test Diagnostic Procedure - Static Test
Connect the diagnostic scan tool (DST) to a power source that is not interrupted when the ignition switch changes positions. With the ignition switch in the RUN position, set the DST to monitor the powertrain control module (PCM) throttle position PID while the speed control actuator carries out the self-test.
Enter self-test diagnostics by firmly pressing and holding the speed control OFF switch while quickly cycling the ignition switch from RUN-to-OFF-to-RUN, making sure the engine does not start and is not running.
The speed control indicator lamp on the instrument panel will flash once to indicate that the speed control module has entered the self test diagnostic mode. Release the OFF switch. If 5 flashes are displayed at this point, a speed control subsystem concern exists. Refer to the Symptom Chart in the vehicle WSM.
Then firmly press and release the remaining switches WITHIN 1 SECOND of each other in the sequence below. The speed control indicator lamp flashes once after each of the buttons is successfully pressed.
NOTE MONITOR THE PCM THROTTLE POSITION PID AFTER THE LAST BUTTON IS PRESSED.
NOTE THERE WILL BE A SLIGHT DELAY FROM WHEN THE LAST BUTTON IS PRESSED AND THE CLUSTER LAMP FLASHES DIAGNOSTIC CODES.
NOTE IF THE SELF-TEST WILL NOT START OR CANNOT BE COMPLETED AFTER MULTIPLE ATTEMPTS, GO TO THE VEHICLE WSM SYMPTOM CHART.
Follow the list below for diagnostic flash codes, then go to the WSM Symptom Chart.
Self Test Diagnostic Procedure - Dynamic Test
NOTE THE DYNAMIC TEST OCCURS AUTOMATICALLY AFTER THE STATIC TEST PASSES. IF THE STATIC TEST FAILS RESULTING IN FLASH CODES, THERE WILL BE NO DYNAMIC PULL TEST.
Within .25 seconds after the static test has completed, the speed control actuator carries out a dynamic pull test. The actuator automatically pulls the speed control cable .04 to .39" (1 to 10 mm) to move the throttle from the idle position and then releases the speed control cable returning the throttle to the idle position.
NOTE THE 2001-2005 ESCAPE/MARINER HOLDS THE PEAK THROTTLE PULL FOR 3 SECONDS PRIOR TO RELEASING.
If the throttle position PID voltage value does not change during the dynamic throttle pull, go to the WSM Symptom Chart Section for Dynamic Pull Test failure.