Mazda 6 2002 Workshop Manual page 1034

ON-BOARD DIAGNOSTIC [CRUISE CONTROL SYSTEM]
DTC 31
DTC 31 Brake switch
DETECTION • Voltage detected at cruise actuator connector terminal C is not approimately 12 V or voltage detected
CONDITION at cruise actuator connector terminal K is not approimately 0 V.
• Burnt STOP 15 A fuse
• Cruise actuator malfunction
POSSIBLE • Brake switch and/or brake switch 2 malfunction
CAUSE • Open circuit in wiring harness between STOP 15 A fuse and brake switch
• Open circuit in wiring harness between brake switch and cruise actuator terminal C
• Short circuit in wiring harness between brake switch 2 and cruise actuator terminal K
Diagnostic procedure
STEP
1 VERIFY WHICH BRAKE SWITCH CIRCUIT IS
MALFUNCTIONING
• Does brake light illuminate when brake pedal
depressed?
2 INSPECT STOP 15 A FUSE FOR FUSION
• Is STOP 15 A fuse okay?
* 3 INSPECT WIRING HARNESS BETWEEN
STOP 15 A FUSE AND BRAKE SWITCH FOR
CONTINUITY
• Depress brake pedal.
• Is voltage at brake switch connector terminal
D approimately 12 V?
* 4 INSPECT WIRING HARNESS BETWEEN
STOP 15 A FUSE AND BRAKE SWITCH FOR
CONTINUITY
• Is voltage at brake switch connector terminal
B approimately 12 V?
* 5 INSPECT WIRING HARNESS BETWEEN
BRAKE SWITCH AND BRAKE LIGHT FOR
CONTINUITY
• Depress brake pedal.
• Is voltage at brake light connector terminal
(power supply side) approimately 12 V?
* 6 INSPECT WIRING HARNESS BETWEEN
BRAKE SWITCH AND CRUISE ACTUATOR
FOR CONTINUITY
• Depress brake pedal.
• Is voltage at cruise actuator connector
terminal C approimately 12 V?
T–182
INSPECTION
Yes Go to Step 6.
No Go to net step.
Yes Go to net step.
No Replace fuse after inspecting and repairing wiring harness.
Yes Go to Step 5.
No Go to net step.
Yes Inspect brake switch.
(See P–8 BRAKE SWITCH
No Repair wiring harness. (STOP 15 A fuse—Brake switch)
Yes Inspect following electrical parts.
• Brake light bulb
• Wiring harness between brake light and ground
No Repair wiring harness. (Brake switch—Brake light)
Yes Go to net step.
No Repair wiring harness. (Cruise actuator—Brake switch)
A6E817266350W05
ACTION
INSPECTION)