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Test TC-15A: Speed Control Solenoid Circuits

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For component location and wiring diagram, see WIRING DIAGRAMS article.
  1. Using scan tool, actuate Speed Control (S/C) vent solenoid. If vent solenoid does not click, go to step 7)  . If vent solenoid clicks, go to next step.
  2. Wiggle wiring harness from S/C servo and brakelight switch to Powertrain Control Module (PCM). Ensure scan tool is still actuating S/C vent solenoid. If vent solenoid stops actuating while wiggling wiring harness, repair wiring as necessary and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If vent solenoid continues actuating, go to next step.
  3. Actuate S/C vacuum solenoid. If vacuum solenoid does not click, go to step 7)  . If vacuum solenoid clicks, go to next step.
  4. Wiggle wiring harness from S/C servo and brakelight switch to Powertrain Control Module (PCM). Ensure scan tool is still actuating S/C vacuum solenoid. If vacuum solenoid stops actuating while wiggling wiring harness, repair wiring as necessary and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If vacuum solenoid continues actuating, go to next step.
  5. Condition required to set DTC is not present at this time. SPEED CONTROL SOLENOID CIRCUITS DTC sets if Powertrain Control Module (PCM) actuates S/C vacuum and vent solenoids but they do not respond. Possible causes are: open or shorted solenoid control circuit, open or shorted S/C vacuum or vent solenoid, open or shorted S/C power supply circuit, or defective PCM. Go to next step.
  6. Inspect all related wiring and connectors. Repair wiring and connectors as necessary and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If wiring and connectors are okay, see INACTIVE DTC CONDITION . Test is complete. Perform TEST VER-2A: ROAD TEST VERIFICATION .
    NOTE: DO NOT depress brake pedal during following steps.
  7. Turn ignition off. Disconnect S/C servo 4-pin connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If connector and terminals are okay, go to next step.
  8. On AB body, go to next step. On all other bodies, turn ignition on, engine off. Turn S/C switch on. Using scan tool, actuate S/C solenoids. Using an external voltmeter, check voltage on S/C servo 4-pin connector, S/C brake switch output circuit (Dark Blue/Light Green wire on ZJ body; Dark Blue/Red wire on all other bodies). If voltage is more than 10 volts, go to step 15)  . If voltage is 10 volts or less, go to step 10)  .
  9. Using scan tool, actuate S/C solenoids. Connect a test light between ground and S/C brake switch output circuit (Dark Blue/Red wire). If test light illuminates, go to step 15)  . If test light does not illuminate, go to next step.
  10. Turn ignition off. Using scan tool in ohmmeter mode, check resistance between ground and S/C servo 4-pin connector, S/C brake switch output circuit (Dark Blue/Light Green wire on ZJ body; Dark Blue/Red wire on all other bodies). If resistance is less than 5 ohms, repair short to ground in S/C brake switch output circuit and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If resistance is 5 ohms or more, go to next step.
  11. On AB body, go to next step. On all other bodies, disconnect brakelight switch connector. Turn ignition on, engine off. Using scan tool, actuate S/C solenoid and check voltage on brakelight switch connector, S/C power supply circuit (Yellow/Red wire). If voltage is 10 volts or less, perform TEST TC-15B: SPEED CONTROL SOLENOID CIRCUITS OR SPEED CONTROL POWER RELAY CIRCUITS . If voltage is more than 10 volts on TJ, XJ and ZJ bodies, perform TEST TC-15C: SPEED CONTROL SOLENOID CIRCUITS OR SPEED CONTROL POWER RELAY CIRCUITS . On all other bodies, go step 13)  .
  12. Disconnect brakelight switch connector. Turn ignition on, engine off. Using scan tool, actuate S/C solenoid. Connect a test light between ground and brakelight switch connector, S/C power supply circuit (Yellow/Red wire). If test light illuminates, perform TEST TC-15B: SPEED CONTROL SOLENOID CIRCUITS OR SPEED CONTROL POWER RELAY CIRCUITS . If test light does not illuminate, go step next step.
  13. Turn ignition off. Disconnect Powertrain Control Module (PCM) connectors. Inspect connectors and terminals for damage. Repair connectors and terminals as necessary and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If connectors and terminals are okay, go to next step.
  14. Using scan tool in ohmmeter mode, check resistance of S/C power supply circuit (Yellow/Red wire) between PCM Gray connector and S/C servo 4-pin connector. If resistance is less than 5 ohms, replace PCM and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If resistance is 5 ohms or more, repair open S/C power supply circuit and perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  15. Turn ignition off. Disconnect battery. Using an external ohmmeter, check resistance between ground and S/C servo 4-pin connector, ground circuit (Black wire). If resistance is 5 ohms or more, repair open ground circuit and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If resistance is less than 5 ohms, go to next step.
  16. Disconnect Powertrain Control Module (PCM) connectors. Inspect connectors and terminals for damage. Repair connectors and terminals as necessary and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If connectors and terminals are okay, go to next step.
  17. Using an external ohmmeter, check resistance of S/C vacuum solenoid control circuit (Tan/Red wire) between PCM Gray connector and S/C servo 4-pin connector. If resistance is 5 ohms or more, repair open S/C vacuum solenoid control circuit and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If resistance is less than 5 ohms, go to next step.
  18. Check resistance of S/C vent solenoid control circuit (Light Green/Red wire) between PCM Gray connector and S/C servo 4-pin connector. If resistance is 5 ohms or more, repair open S/C vent solenoid control circuit and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If resistance is less than 5 ohms, go to next step.
  19. Check resistance between ground and S/C servo 4-pin connector, S/C vacuum solenoid control circuit (Tan/Red wire). If resistance is 5 ohms or more, repair short to ground in S/C vacuum solenoid control circuit and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If resistance is less than 5 ohms, go to next step.
  20. Check resistance between ground and S/C servo 4-pin connector, S/C vent solenoid control circuit (Light Green/Red wire). If resistance is less than 5 ohms, repair short to ground in S/C vent solenoid control circuit and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If resistance is less than 5 ohms on AB, AN, BE/BR and DN bodies, replace S/C servo and perform TEST VER-4A: SPEED CONTROL VERIFICATION . On TJ, XJ and ZJ bodies, go to next step.
  21. Reconnect PCM connectors. Turn ignition on, engine off. Using scan tool, actuate S/C solenoids. Using an external voltmeter, check voltage between S/C servo 4-pin connector, S/C vent solenoid control circuit (Light Green/Red wire) and S/C brake switch output circuit (Dark Blue/Red wire). If voltage is 10 volts or less, replace PCM and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If voltage is more than 10 volts, go to next step.
  22. Check voltage between S/C servo 4-pin connector, S/C vacuum solenoid control circuit (Tan/Red wire) and S/C brake switch output circuit (Dark Blue/Red wire). If voltage is 10 volts or less, replace PCM and perform TEST VER-4A: SPEED CONTROL VERIFICATION . If voltage is more than 10 volts, replace S/C servo and perform TEST VER-4A: SPEED CONTROL VERIFICATION .
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