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DTC P0703: BRAKE SWITCH INPUT MALFUNCTION (A/T) Subaru Forester SF рестайлинг

Testing & Diagnostics ~481 words
  1. Perform basic diagnostic procedure. See «BASIC DIAGNOSTIC PROCEDURE»(ref-11745-S33755862182000112700000) . Using a helper, depress brake pedal and check if brake lights illuminate. If brake lights illuminate, go to next step. If brake lights do not illuminate, repair brake light circuit as required. Clear memory and perform verification procedure. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-11745-S21987207372000112700000) and «VERIFICATION PROCEDURE»(ref-11745-S19795024722001010900000) .
  2. Turn ignition off. Locate transmission control module (TCM) under left side of dash and disconnect Gray 24-pin electrical harness connector B55. Disconnect 2-pin (4-pin on models with cruise control) electrical harness connector from brake light switch. Using a DVOM, measure resistance of White/Black wire between Gray 24-pin TCM electrical harness connector terminal No. 24 and brake light switch terminal No. 2 (No. 1 on Impreza and Outback Sport) on models without cruise control or brake light switch terminal No. 3 on models with cruise control. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open circuit in wiring and check for poor terminal contact in all connectors between TCM and brake light switch. See TRANSMISSION in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Clear memory and perform verification procedure. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-11745-S21987207372000112700000) and «VERIFICATION PROCEDURE»(ref-11745-S19795024722001010900000) .
  3. Using a DVOM, measure resistance of White/Black wire between Gray 24-pin TCM electrical harness connector terminal No. 24 and good chassis ground point. If resistance is more than one megohm, go to next step. If resistance is not more than one megohm, repair short to ground in wiring between TCM and brake light switch. Clear memory and perform verification procedure. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-11745-S21987207372000112700000) and «VERIFICATION PROCEDURE»(ref-11745-S19795024722001010900000) .
  4. Turn ignition off. Reconnect Gray 24-pin TCM electrical harness connector and brake light switch electrical harness connector. Using a DVOM, measure voltage of White/Black wire by backprobing between Gray 24-pin TCM terminal No. 24 and good chassis ground point with brake pedal released. If voltage is less than one volt with brake pedal released, go to next step. If voltage is not less than one volt with brake pedal released, adjust or replace brake light switch. Clear memory and perform verification procedure. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-11745-S21987207372000112700000) and «VERIFICATION PROCEDURE»(ref-11745-S19795024722001010900000) .
  5. Using a DVOM, measure voltage of White/Black wire by backprobing between Gray 24-pin TCM terminal No. 24 and good chassis ground point with brake pedal depressed. If voltage is more than 10 volts with brake pedal depressed, go to next step. If voltage is not more than 10 volts with brake pedal depressed, adjust or replace brake light switch. Clear memory and perform verification procedure. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-11745-S21987207372000112700000) and «VERIFICATION PROCEDURE»(ref-11745-S19795024722001010900000) .
  6. Check for poor terminal contact in TCM connector. Repair poor contact as necessary. If TCM connector is okay, replace TCM. Clear memory and perform verification procedure. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-11745-S21987207372000112700000) and «VERIFICATION PROCEDURE»(ref-11745-S19795024722001010900000) .

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