Mazda CX-9 Grand Touring 2009 Manual page 493

DTC C1446 [DSC/RSC] DIAGNOSTIC PROCEDURE
STEP INSPECTION
VERIFY OPEN OR SHORT CIRCUIT
IN BRAKE SWITCH SIGNAL
Turn the ignition switch to the ON
position.
Measure the voltage between the
PCM terminal 1T and body ground
when the brake pedal is depressed
1
and released:
Voltage
Brake pedal depressed: B+
Brake pedal released:
1 V or less
INSPECT BRAKE SWITCH SIGNAL
FOR SHORT TO POWER SUPPLY
CIRCUIT
Disconnect the brake switch
connector.
2
Measure the voltage between the
brake switch connector terminal D
(vehicle harness-side) and body
ground.
Is the voltage 1 V or less ?
INSPECT BRAKE SWITCH SIGNAL
FOR OPEN CIRCUIT
Disconnect the PCM connectors.
Disconnect the brake switch
connector.
3
Inspect continuity between the PCM
connector terminal 1T (vehicle
harness-side) and brake switch
terminal D:
Is there continuity?
INSPECT BRAKE SWITCH
Inspect the brake switch.
2008 Mazda CX-9 Grand Touring
2008 BRAKES On-Board Diagnostic (DSC/RSC) - Mazda CX-9
Yes Go to Step 5.
No
Yes Go to Step 4.
No
Yes Go to the next step.
No
Yes Go to the next step.
ACTION
If it is B+ under any condition, then go to the next
step. If it is 1 V or less under any condition, then
go to Step 3.
Repair or replace the wiring harness between the
PCM and brake switch, then go to Step 5
Repair or replace the wiring harness between the
PCM and brake switch, then go to Step 5.