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412-02-21 412-02-21 Heating and Ventilation DIAGNOSIS AND TESTING (Continued) PINPOINT TEST K: DTC B2513 BLOWER (FAN) CIRCUIT FAILURE TEST STEP ACTION TO TAKE K1 RETRIEVE CONTINUOUS DIAGNOSTIC TROUBLE CODES (DTCs) FROM INTERFACE ADAPTER ASSEMBLY (IAA) MODULE WHILE IN PANEL/FLOOR MODE • With key ON, set the mode select knob to the PANEL/FLOOR position Yes = GO to and the temperature control knob to the full warm position. • Wait approximately 45 seconds and retrieve continuous DTCs from the No = GO to K2. IAA module. • Do DTC B2516 Blower Control Circuit Failure and DTC C1776 Heater System Failure occur? K2 CHECK BLOWER/FAN STATUS • With key ON, set the mode select knob to the PANEL/FLOOR position Yes = System OK. CHECK wiring and monitor the IAA module PIDs BLOWER and BFSV while rotating for intermittent connections. the blower control knob through all the blower speed positions and verify the voltages below: — LOW = 9.8-10.4 volts 1 = 6.8-7.4 volts — MED 2 = 3.9-4.5 volts — HIGH = 1.4-2.1 volts • Are the voltages correct? No = GO to K3. K3 CHECK FUSE AND POWER TO BLOWER MOTOR RELAY • Check 40A fuse 21 in the electric vehicle power distribution box Yes = RECONNECT the blower (EVPDB). motor relay. GO to K4. • With key OFF, remove the blower motor relay from the EVPDB and No = REPAIR as necessary. measure the voltage between pins 85, 87 on the blower motor relay connector and ground. (V > 10 volts) • Is everything OK? K4 CHECK BLOWER MOTOR • With key OFF, disconnect VBC C1971. Yes = GO to K5. • With key ON, set the mode select knob to the PANEL/FLOOR position No = and connect a jumper wire between pin 4 (P/W wire) on VBC C1971 and ground. • Does the blower motor operate? K5 CHECK VBC FEEDBACK SIGNAL • With key OFF, reconnect VBC C1971. Yes = REPLACE the IAA module. REFER to • Connect 104-Pin Breakout Box (BOB) to IAA module and IAA module No = GO to K6. C1945. NOTE: The mode select knob must be in the OFF position when carrying out this test step. • With key ON, set the mode select knob to the OFF position and measure the voltage between BOB pin 64 and ground (BOB pin 80). • Is the voltage greater than 10 volts? K6 CHECK CIRCUIT 148 (Y/R) FOR OPEN • With key OFF, disconnect BOB from the IAA module; leave BOB Yes = GO to K7. connected to IAA module C1945. • With key OFF, disconnect VBC C1971 and measure the resistance of the No = REPAIR the Y/R wire. Y/R wire between pin 1 on VBC C1971 and BOB pin 64. • Is the resistance less than 5 ohms? K7 CHECK CIRCUIT 148 (Y/R) FOR SHORT TO GROUND • With key OFF, measure the resistance between BOB pin 64 and ground Yes = REPLACE the VBC. (BOB pin 80). REFER to (Continued) |