2002 Chrysler Voyager ECFACTORY OEM SERVICE PROCEDURE

Rear Keyboard Fault

NOTE: After making any repairs, perform BODY VERIFICATION TEST  under VERIFICATION TESTS.
  1. Turn ignition switch to OFF position. Disconnect rear zone control panel harness connector. Using DVOM measure resistance between ground and rear zone control panel connector terminal No. 2 (Black/Dark Green wire). If reading is less than 5 ohms, go to next step. If reading is 5 ohms or more, locate and repair open between ground and Black/Dark Green wire. After repair, calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING.
  2. Turn ignition switch to ON position. Using DVOM, measure voltage between ground and rear zone control panel connector terminal NO. 1 (Gray/Pink wire). If reading is 10 volts or more, go to next step. If reading is less than 10 volts, go to step  13.
  3. Using DVOM, measure voltage in White/Dark Green wire between ATC module connector C2 terminal No. 10 and rear zone control panel connector terminal No. 4. If reading is 10 volts or more, go to next step. If reading is less than 10 volts, go to step  11.
  4. Turn ignition switch to OFF position. Disconnect ATC module C2 connector. Turn ignition switch to ON position. Using DVOM, measure voltage in White/Dark Blue wire between ATC module C2 connector terminal No. 10 and rear zone control panel connector terminal No. 4. See Figure. If reading is less than one volt, go to next step. If reading is one volt or more, repair short to voltage in White/Dark Green wire. After repair, calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING.
  5. Turn ignition switch to OFF position. Connect ATC module connector C2. Set up lab scope (oscilloscope) for 12-volt square wave pattern. Set lab scope voltage range to 20 volts with an offset of 4 volts. Set lab scope to 40-millisecond division (40ms/div) scale. Connect lab scope ground lead to chassis ground. Connect lab scope probe lead to rear zone control panel connector terminal No. 3 (White/Tan wire). See Figure. Turn ignition switch to ON position. If lab scope pattern is good and cycles from approximately 0 to 8 volts, go to next step. If voltage pattern is erratic or does not cycle between about 0 and 8 volts, go to step  7.
  6. Turn ignition switch to OFF position. Replace rear zone control panel. After repair, calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING.
  7. Turn ignition switch to OFF position. Disconnect ATC module connector C2. Turn ignition switch to ON position. Using DVOM, measure voltage in White/Tan wire between ATC module C2 connector terminal No. 9 and rear zone control panel connector terminal No. 3. See Figure and Figure . If reading is less than one volt, go to next step. If reading is one volt or more, repair short to voltage in White/Tan wire. After repair, calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING.
  8. Turn ignition switch to OFF position. Using DVOM, measure resistance between ground and ATC module C2 connector terminal No. 9 (White/Tan wire). See Figure. If reading is less than 100 k/ohms, repair short to ground in White/Tan wire. After repair, calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING. If reading is 100 k/ohms or more, go to next step.
  9. Using DVOM, measure resistance in White/Tan wire between ATC module C2 connector terminal No. 9 and rear zone control panel connector terminal No. 3. See Figure and Figure . If reading is less 5 ohms, go to next step. If reading is 5 ohms or more, repair open in White/Tan wire. After repair, calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING.
  10. Turn ignition switch to OFF position. Replace ATC module. Calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING.
  11. Turn ignition switch to OFF position. Using DVOM, measure resistance between ground and ATC module C2 connector terminal No.10 (White/Dark Green wire). See Figure. If reading is less than 100 k/ohms, repair short to ground in White/Dark Green wire. After repair, calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING. If reading is 100 k/ohms or more, go to next step.
  12. Turn ignition switch to OFF position. Using DVOM, measure resistance in White/Dark Green wire between ATC module C2 connector terminal No. 9 and rear zone control panel connector terminal No. 3. See Figure and Figure . If reading is less 5 ohms, go to step  10. If reading is 5 ohms or more, repair open in White/Dark Green wire. After repair, calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING.
  13. Turn ignition switch to OFF position. Disconnect Body Control Module (BCM) connector C4. See Figure. Measure resistance in Gray/Pink wire between rear zone control panel connector terminal No. 1 and BCM connector C4 terminal No. 10. See Figure. If reading is less than 5 ohms, replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. If reading is 5 ohms or more, repair open on Gray/Pink wire. After either repair, calibrate ATC module. See HVAC CONTROL CALIBRATION  under PROGRAMMING.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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