DTC C0040-23: Brake Switch (No. 1 Signal) Circuit Malfunction [Start Stop Unit]: Notes

DTC C0040:23 (START STOP UNIT) DETECTION CONDITION AND POSSIBLE CAUSE

Description	Brake switch (No. 1 signal) circuit malfunction
Detection condition	The start stop unit detected the following condition 5 times continuously with the ignition switched ON (engine off or on). The brake switch (No. 1 signal) is OFF for a continuous 3 s or more even though the brake switch (No. 2 signal) changes.
Fail-safe	Determined by brake switch (No. 2 signal) with the brake pedal depressed.
Possible cause	Brake switch connector or terminal malfunction Brake switch (No. 1 signal) malfunction Brake switch (No. 1 signal) power supply circuit malfunction Short to ground in wiring harness between MAIN 200 A fuse and brake switch terminal A STOP 10 A fuse malfunction MAIN 200 A fuse malfunction Open circuit in wiring harness between battery positive terminal and brake switch terminal A Start stop unit connector or terminal malfunction Short to ground in wiring harness between brake switch terminal D and start stop unit terminal 1C Open circuit in wiring harness between brake switch terminal D and start stop unit terminal 1C Start stop unit malfunction
Courtesy of MAZDA MOTORS CORP.