Mazda CX-9 Grand Touring. Manual — part 124

DTC C1446 [DSC/RSC] DIAGNOSTIC PROCEDURE

STEP

INSPECTION

ACTION

1

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
and released:

Voltage

Brake pedal depressed: B+

Brake pedal released:

1 V or less

Yes Go to Step 5.

No

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.

2

INSPECT BRAKE SWITCH SIGNAL
FOR SHORT TO POWER SUPPLY
CIRCUIT



Disconnect the brake switch
connector.



Measure the voltage between the
brake switch connector terminal D
(vehicle harness-side) and body
ground.



Is the voltage 1 V or less ?

Yes Go to Step 4.

No

Repair or replace the wiring harness between the

PCM and brake switch, then go to Step 5

3

INSPECT BRAKE SWITCH SIGNAL
FOR OPEN CIRCUIT



Disconnect the PCM connectors.



Disconnect the brake switch
connector.



Inspect continuity between the PCM
connector terminal 1T (vehicle
harness-side) and brake switch
terminal D:



Is there continuity?

Yes Go to the next step.

No

Repair or replace the wiring harness between the

PCM and brake switch, then go to Step 5.

INSPECT BRAKE SWITCH



Inspect the brake switch.

Yes Go to the next step.

2008 Mazda CX-9 Grand Touring

2008 BRAKES On-Board Diagnostic (DSC/RSC) - Mazda CX-9

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Sunday, November 15, 2009 9:50:13 AM

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DTC C1963 [DSC/RSC]

DTC C1963 [DSC/RSC] DETECTION CONDITION AND POSSIBLE CAUSE

DIAGNOSTIC PROCEDURE

DTC C1963 [DSC/RSC] DIAGNOSTIC PROCEDURE

4

(See BRAKE SWITCH
INSPECTION .)



Is the brake switch normal?

No

Replace the brake switch, then go to the next step.

(See BRAKE PEDAL

REMOVAL/INSTALLATION .)

5

VERIFY THAT THE SAME DTC IS
NOT PRESENT



Reconnect all disconnected
connectors.



Clear the DTCs from the memory.

(See ON-BOARD DIAGNOSTIC
[DSC/RSC].)



Are the same DTCs present?

Yes

Repeat the inspection from Step 1.
If the malfunction recurs, replace the DSC/RSC
HU/CM, then go to the next step.
(See DSC/RSC HU/CM
REMOVAL/INSTALLATION .)

No

Go to the next step.

6

VERIFY THAT NO OTHER DTCS
ARE PRESENT



Are any other DTCs output?

Yes

Go to the applicable DTC inspection.
(See ON-BOARD DIAGNOSTIC [DSC/RSC].)

No

DTC troubleshooting completed.

NOTE:



The initial point of the combined sensor (yaw rate sensor part) is corrected
based on the signals from each sensor while the vehicle is driven straight,
however, the correction cannot be performed if the vehicle is continuously
driven on a curve and DTC C1963 is detected.

DTC C1963

Combined sensor (Yaw rate sensor part) initial point correction error

DETECTION

CONDITION



When a difference occurs between the estimated yaw rate value which is
calculated by each sensor and the yaw rate value which is detected by the
combined sensor (yaw rate sensor part).

POSSIBLE

CAUSE



It occurs since the initial point correction for the combined sensor (yaw rate
sensor part) cannot be performed due to the vehicle being continuously driven
on a curve, and does not indicate an DSC/RSC system malfunction.

STEP

INSPECTION

ACTION

PERFORM INITIALIZATION
PROCEDURE



Perform the initialization

2008 Mazda CX-9 Grand Touring

2008 BRAKES On-Board Diagnostic (DSC/RSC) - Mazda CX-9

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Sunday, November 15, 2009 9:50:13 AM

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© 2005 Mitchell Repair Information Company, LLC.

DTC C1991 [DSC/RSC]

DTC C1991 [DSC/RSC] DETECTION CONDITION AND POSSIBLE CAUSE

DIAGNOSTIC PROCEDURE

DTC C1991 [DSC/RSC] DIAGNOSTIC PROCEDURE

1

procedure for the combined
sensor.

(See DSC/RSC SENSOR
INITIALIZATION
PROCEDURE .)

After the initialization procedure for the combined
sensor has been completed, go to the next step.

2

VERIFY DTC
TROUBLESHOOTING
COMPLETED



Clear the DTC from the memory.

(See ON-BOARD
DIAGNOSTIC [DSC/RSC].)



Start the engine and drive the
vehicle at 72 km/h {45 mph} or
more.



Is the same DTC present?

Yes

Repeat the inspection from Step 1.
If the malfunction occurs again, replace the
DSC/RSC HU/CM, then go to the next step.
(See DSC/RSC HU/CM
REMOVAL/INSTALLATION .)

No

Go to the next step.

3

VERIFY AFTER REPAIR
PROCEDURE



Are any other DTCs present?

Yes

Go to the applicable DTC inspection.
(See ON-BOARD DIAGNOSTIC [DSC/RSC].)

No

DTC troubleshooting completed.

DTC C1991

DSC/RSC sensor (abnormal initialization) system

DETECTION

CONDITION



The DSC/RSC sensor detects that the initialization procedure has not
been performed.

POSSIBLE CAUSE



The initialization procedure for the DSC/RSC sensor has not been
performed.

STEP

INSPECTION

ACTION

1

VERIFY INITIALIZATION
PROCEDURE.



Has the DSC/RSC sensor
initialization procedure been
performed?

Yes Go to the next step.

No

Perform the DSC/RSC sensor initialization procedure,

then go to the next step. (See DSC/RSC SENSOR

INITIALIZATION PROCEDURE .)

VERIFY DTC

2008 Mazda CX-9 Grand Touring

2008 BRAKES On-Board Diagnostic (DSC/RSC) - Mazda CX-9

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Sunday, November 15, 2009 9:50:13 AM

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© 2005 Mitchell Repair Information Company, LLC.

DTC U1901 [DSC/RSC]

DTC U1901 [DSC/RSC] DETECTION CONDITION AND POSSIBLE CAUSE

2

TROUBLESHOOTING
COMPLETED



Clear the DTC from the
memory.

(See ON-BOARD
DIAGNOSTIC
[DSC/RSC].)



Is the same DTC present?

Yes

Repeat the inspection from Step 1.
If the malfunction occurs again, replace the DSC/RSC
HU/CM, then go to the next step.
(See DSC/RSC HU/CM
REMOVAL/INSTALLATION .)

No

Go to the next step.

3

VERIFY AFTER REPAIR
PROCEDURE



Are any other DTCs present?

Yes

Go to the applicable DTC inspection.
(See ON-BOARD DIAGNOSTIC [DSC/RSC].)

No

DTC troubleshooting completed.

DTC U1901

Combined sensor system (CAN2 line malfunction)

DETECTION

CONDITION



The signal from the combined sensor is not within specification.

POSSIBLE CAUSE



Open or short circuit in the CAN2_L wiring harness between combined sensor
terminal C and DSC/RSC HU/CM terminal M



Open or short circuit in the CAN2_H wiring harness between combined sensor
terminal D and DSC/RSC HU/CM terminal P



Combined sensor malfunction



DSC/RSC HU/CM malfunction



Poor connection at connectors (female terminal)

2008 Mazda CX-9 Grand Touring

2008 BRAKES On-Board Diagnostic (DSC/RSC) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 9:50:13 AM

Page 40

© 2005 Mitchell Repair Information Company, LLC.