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Checking Speed Control Operation

NOTE: Perform this test only if there are no Diagnostic Trouble Codes (DTCs).
  1. Turn ignition on. While monitoring scan tool, press brake pedal several times. If scan tool displays brake pedal PRESSED and RELEASED, go to next step. If scan tool does not display brake pedal PRESSED and RELEASED, go to BRAKE SWITCH SENSE STATUS DOES NOT CHANGE ON SCAN TOOL .
  2. Turn ignition off. Disconnect S/C servo connector. Using DVOM, measure resistance between ground and S/C servo connector terminal No. 4 (Black wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire. Perform TEST VER-4A  under VERIFICATION TESTS.
  3. While observing scan tool, monitor Speed Control (S/C) switch inputs. Turn S/C switch on and off several times. If scan tool displays S/C switch PRESSED and RELEASED, go to next step. If scan tool does not display S/C switch PRESSED and RELEASED, go to step  16.
  4. Inspect S/C servo connector terminals and wiring between servo, brake switch and S/C switch. If terminals and circuits are okay, go to next step. If any terminal is damaged, pushed out or miswired, repair as necessary. Perform TEST VER-4A  under VERIFICATION TESTS.
  5. Move gear selector to Drive. If scan tool displays Park Neutral (P/N) switch D/R, go to next step. If scan tool does not display P/N switch D/R, go to PARK/NEUTRAL POSITION (PNP) SWITCH (AUTOMATIC TRANSMISSION) .
  6. Turn ignition off. Inspect throttle cable. If throttle cable is okay, go to next step. If throttle cable is disconnected or damaged, repair as necessary. Perform TEST VER-4A  under VERIFICATION TESTS.
  7. While observing scan tool, press SET switch several times. If scan tool displays PRESSED and RELEASED, go to next step. If scan tool does not display PRESSED and RELEASED, replace left S/C switch. See SPEED CONTROL SWITCH  under REMOVAL & INSTALLATION. Perform TEST VER-4A  under VERIFICATION TESTS.
  8. While observing scan tool, press resume switch several times. If scan tool displays resume switch PRESSED or RELEASED, go to next step. If scan tool does not display resume switch PRESSED or RELEASED, go to step  12.
  9. Turn ignition on. Use scan tool to check for DTCs. If no vehicle speed DTCs are set, go to next step. If DTC P0500 is set, go to DTC P0500: NO VEHICLE SPEED SENSOR SIGNAL  under DIAGNOSTIC TESTS.
  10. Press cancel switch several times. If scan tool displays cancel switch PRESSED or RELEASED, go to next step. If scan tool does not display cancel switch PRESSED or RELEASED, replace right S/C switch. See SPEED CONTROL SWITCH  under REMOVAL & INSTALLATION. Perform TEST VER-4A  under VERIFICATION TESTS.
  11. Press coast switch several times. If scan tool displays coast switch PRESSED or RELEASED, go to step  42. If scan tool does not display coast switch PRESSED or RELEASED, replace right S/C switch. See SPEED CONTROL SWITCH  under REMOVAL & INSTALLATION. Perform TEST VER-4A  under VERIFICATION TESTS.
  12. Turn ignition on. Use scan tool to check for DTCs. If no vehicle speed DTCs are set, go to next step. If DTC P0500 is set, go to DTC P0500: NO VEHICLE SPEED SENSOR SIGNAL  under DIAGNOSTIC TESTS.
  13. Disconnect S/C resume/accel switch connector. Using DVOM, measure resistance between ground circuit at S/C resume/accel switch connector and ground. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in ground circuit for S/C resume/accel switch. Perform TEST VER-4A  under VERIFICATION TESTS.
  14. With S/C resume/accel switch connector disconnected, disconnect S/C on/off switch connector. Using DVOM, measure resistance of speed control switch signal circuit between S/C on/off switch and S/C resume/accel switch connectors. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in speed control switch signal circuit for S/C. Perform TEST VER-4A  under VERIFICATION TESTS.
  15. Connect a jumper wire between speed control switch signal and ground circuit terminals at S/C resume/accel switch connector. Turn ignition on. Use scan tool to read S/C switch voltage. If scan tool indicates greater than one volt, go to next step. If scan tool indicates one volt or less, replace right S/C switch. See SPEED CONTROL SWITCH  under REMOVAL & INSTALLATION. Perform TEST VER-4A  under VERIFICATION TESTS.
  16. Inspect S/C switch connector terminals and wiring. If terminals and circuits are okay, go to next step. If any terminal is damaged, pushed out or miswired, repair as necessary. Perform TEST VER-4A  under VERIFICATION TESTS.
  17. Turn engine on and allow to idle. Use scan tool to read S/C switch voltage. If scan tool indicates greater than 4 volts, go to next step. If scan tool indicates than 4 volts or less, go to step  29.
  18. Turn ignition on, engine off. Monitor P/N switch inputs. Move gear selector to Drive. If scan tool displays P/N switch D/R, go to next step. If scan tool does not display P/N switch D/R, go to PARK/NEUTRAL POSITION (PNP) SWITCH (AUTOMATIC TRANSMISSION) .
  19. Turn ignition off. Inspect throttle cable. If throttle cable is okay, go to next step. If throttle cable is disconnected or damaged, repair as necessary. Perform TEST VER-4A  under VERIFICATION TESTS.
  20. Disconnect both left and right S/C switch connectors. Measure resistance of speed control switch signal circuit and ground circuit between left and right switch connectors. If resistance is less than 5 ohms for both circuits, go to next step. If resistance is 5 ohms or more for both circuits, replace clockspring. See AIR BAG RESTRAINT SYSTEMS - CARS article. Perform TEST VER-4A  under VERIFICATION TESTS.
  21. Disconnect clockspring connector below steering column. Measure resistance of speed control switch ground circuit between clockspring connector terminal No. 7 (Black/Tan wire) and S/C on/off switch connector. See Fig 1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace clockspring. See AIR BAG RESTRAINT SYSTEMS - CARS article. Perform TEST VER-4A  under VERIFICATION TESTS.
  22. Using DVOM, measure resistance of Black/Tan wire between clockspring connector terminal No. 7 and ground. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/Tan wire. Perform TEST VER-4A  under VERIFICATION TESTS.
  23. With S/C on/off switch disconnected, turn switch over and measure resistance between switch terminals. Monitor DVOM reading while pressing S/C on/off switch.If resistance changes from 5 ohms when pressed to open when released, go to next step. If resistance does not change from 5 ohms when pressed to open when released, replace switch. Perform TEST VER-4A  under VERIFICATION TESTS.
  24. Using DVOM, measure voltage between S/C on/off switch connector speed control switch signal terminal and ground. If voltage is less than 6 volts, go to next step. If voltage is greater than 6 volts, repair short to voltage in speed control switch signal circuit.
  25. Turn ignition on. Use scan tool to check for DTCs. If no vehicle speed DTCs are set, go to next step. If DTC P0500 is set, go to DTC P0500: NO VEHICLE SPEED SENSOR SIGNAL  under DIAGNOSTIC TESTS.
  26. Disconnect PCM connector C2. Using DVOM, measure resistance of Red/Light Green wire between PCM connector C2 terminal No. 41 and clockspring connector terminal No. 6. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Red/Light Green wire. Perform TEST VER-4A  under VERIFICATION TESTS.
  27. Using DVOM, measure resistance between clockspring connector terminal No. 6 (clockspring side) and S/C on/off switch connector speed control switch signal terminal. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace clockspring. See AIR BAG RESTRAINT SYSTEMS - CARS article. Perform TEST VER-4A  under VERIFICATION TESTS.
  28. Replace PCM. Perform TEST VER-4A  under VERIFICATION TESTS.
  29. Turn ignition on, engine off. Monitor P/N switch inputs. Move gear selector to Drive. If scan tool displays P/N switch D/R, go to next step. If scan tool does not display P/N switch D/R, go to PARK/NEUTRAL POSITION (PNP) SWITCH (AUTOMATIC TRANSMISSION) .
  30. Turn ignition off. Inspect throttle cable. If throttle cable is okay, go to next step. If throttle cable is disconnected or damaged, repair as necessary. Perform TEST VER-4A  under VERIFICATION TESTS.
  31. Turn ignition on. Use scan tool to read S/C switch voltage. If scan tool indicates less than one volt, go to next step. If scan tool indicates greater than one volt, go to step  39.
  32. Use scan tool to check for DTCs. If no vehicle speed DTCs are set, go to next step. If DTC P0500 is set, go to DTC P0500: NO VEHICLE SPEED SENSOR SIGNAL  under DIAGNOSTIC TESTS.
  33. Disconnect S/C on/off switch connector. Turn ignition on. Use scan tool to read S/C switch voltage. If scan tool reading does not change to 5 volts, go to next step. If scan tool reading changes to 5 volts, replace switch. Perform TEST VER-4A  under VERIFICATION TESTS.
  34. Disconnect S/C resume/accel switch connector. Turn ignition on. Use scan tool to read S/C switch voltage. If scan tool reading does not change to 5 volts, go to next step. If scan tool reading changes to 5 volts, replace switch. Perform TEST VER-4A  under VERIFICATION TESTS.
  35. Disconnect clockspring connector. Turn ignition on. Use scan tool to read S/C switch voltage. If scan tool reading does not change to 5 volts, go to next step. If scan tool reading changes to 5 volts, replace clockspring. See AIR BAG RESTRAINT SYSTEMS - CARS article. Perform TEST VER-4A  under VERIFICATION TESTS.
  36. Turn ignition off. Reconnect clockspring and resume/accel switch connectors. Disconnect PCM connector C2. Measure resistance between S/C on/off switch connector terminals. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short between speed control switch signal and ground circuits. Perform TEST VER-4A  under VERIFICATION TESTS.
  37. Measure resistance between S/C on/off switch speed control switch signal connector terminal and ground. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in speed control switch signal and ground. Perform TEST VER-4A  under VERIFICATION TESTS.
  38. Replace PCM. Perform TEST VER-4A  under VERIFICATION TESTS.
  39. Use scan tool to check for DTCs. If no vehicle speed DTCs are set, go to next step. If DTC P0500 is set, go to DTC P0500: NO VEHICLE SPEED SENSOR SIGNAL  under DIAGNOSTIC TESTS.
  40. Using scan tool, monitor S/C switch voltage. Disconnect S/C on/off switch. If S/C switch voltage does not change from less than 4 volts to greater than 4 volts, go to next step. If S/C switch voltage changes from less than 4 volts to greater than 4 volts, replace switch. Perform TEST VER-4A  under VERIFICATION TESTS.
  41. Using scan tool, monitor S/C switch voltage. Disconnect S/C resume/accel switch. If S/C switch voltage does not change from less than 4 volts to greater than 4 volts, go to next step. If S/C switch voltage changes from less than 4 volts to greater than 4 volts, replace switch. Perform TEST VER-4A  under VERIFICATION TESTS.
  42. Start engine and allow to idle for one minute. Turn engine off. Turn ignition on. Monitor throttle plate in throttle body. Using scan tool, actuate speed control servo solenoids. If throttle plate opens and closes, go to next step. If throttle plate does not open and close, check speed control servo vacuum supply for disconnected or pinched hoses or defective vacuum reserve canister. Repair vacuum supply or replace defective parts as necessary.
  43. At this time speed control switch and servo functions appear to operate properly. Using scan tool, monitor speed control output status. Road test vehicle at speeds greater than 35 MPH. Attempt to set speed control. If speed control fails to set, a DENIED message will be displayed. The last or most recent cause for speed control not to set is indicated by denied status. See SCAN TOOL DENIED STATUS  table. Items listed in table will not allow speed control to set. Correct fault and recheck system operation.
SCAN TOOL DENIED STATUS

Denied Message Reason
ON/OFF PCM Does Not See An ON Signal From Switch At PCM
SPEED Vehicle Speed As Seen By PCM Is Not Greater Than 36 MPH
RPM Engine RPM Is Excessively High
BRAKE Brake Switch Sense Circuit Is Open Indicating That Brakes Are Applied
P/N Park/Neutral Switch Sense Circuit Is Grounded Indicating That Transmission Is In Park Or Neutral
RPM/SPD PCM Senses Excessive Engine RPM For A Given Vehicle Speed
SOL FLT PCM Senses A Servo Solenoid Circuit Trouble Code That Is Maturing Or Set In Memory
Fig 1: Identifying Clockspring Connector Terminals
G00007395Courtesy of CHRYSLER CORP.
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