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412-02-29 412-02-29 Heating and Ventilation DIAGNOSIS AND TESTING (Continued) PINPOINT TEST R: RECIRCULATION FUNCTION DOES NOT OPERATE TEST STEP ACTION TO TAKE • Is the outside/recirculation door in the recirculation position? No = GO to R4. R4 CHECK OPERATION OF RECIRCULATION VACUUM SOLENOID • With key ON, set the mode select knob to the FLOOR/PANEL position. Yes = • Enter the interface adapter assembly (IAA) module active command No = GO to R5. mode CLIMATE CONTROL COMMAND and set the active commands MAINT VAC to YES and RECIR SOL to ON. • Check the position of the outside/recirculation door. • Is the outside/recirculation door in the recirculation position? R5 CHECK POWER TO IN-LINE C2999 • With key OFF, disconnect in-line C2999. Yes = RECONNECT in-line C2999. GO to R9. • With key ON, measure the voltage between pin 8 (Y/LG wire) and pin 7 No = GO to R6. (BK wire) on in-line C2999. • Is the voltage greater than 10 volts? R6 CHECK GROUND TO IN-LINE C2999 • With key OFF, measure the resistance between pin 7 (BK wire) on Yes = GO to R7. in-line C2999 and ground. • Is the resistance less than 5 ohms? No = REPAIR the BK wire. R7 CHECK CIRCUIT 3052 (Y/LG) FOR OPEN • Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave IAA Yes = GO to R8. module disconnected. • With key OFF, measure the resistance of the Y/LG wire between pin 8 No = REPAIR the Y/LG wire. on in-line C2999 and BOB pin 35. • Is the resistance less than 5 ohms? R8 CHECK CIRCUIT 3052 (Y/LG) FOR SHORT TO GROUND • With key OFF, measure the resistance between BOB pin 35 and ground Yes = REPLACE the IAA module. (BOB pin 80). REFER to • Is the resistance greater than 10,000 ohms? No = REPAIR the Y/LG wire. R9 CHECK POWER TO RECIRCULATION VACUUM SOLENOID • With key OFF, disconnect recirculation vacuum solenoid C2994. Yes = GO to R11. • With key ON, measure the voltage between the Y/LG wire and BK wire No = GO to R10. on recirculation vacuum solenoid C2994. • Is the voltage greater than 10 volts? R10 CHECK GROUND TO RECIRCULATION VACUUM SOLENOID • With key OFF, measure the resistance between the BK wire on Yes = GO to R11. recirculation vacuum solenoid C2994 and ground. • Is the resistance less than 5 ohms? No = REPAIR the BK wire. R11 CHECK VACUUM FROM RECIRCULATION VACUUM SOLENOID • With key ON, set the mode select knob to the OFF position, disconnect Yes = CHECK the the white vacuum line from the recirculation vacuum solenoid, and check fresh/recirculation door for vacuum. vacuum motor for vacuum leak. REPLACE if necessary. • Is vacuum present? No = GO to R12. R12 CHECK VACUUM TO RECIRCULATION VACUUM SOLENOID (Continued) |