Mazda CX-9 Grand Touring 2009 Manual page 496

TROUBLESHOOTING
COMPLETED
Clear the DTC from the
memory.
2
(See ON-BOARD
DIAGNOSTIC
[DSC/RSC].)
Is the same DTC present?
VERIFY AFTER REPAIR
PROCEDURE
3
Are any other DTCs present?
DTC U1901 [DSC/RSC]
DTC U1901 [DSC/RSC] DETECTION CONDITION AND POSSIBLE CAUSE
DTC U1901
DETECTION
CONDITION
POSSIBLE CAUSE
2008 Mazda CX-9 Grand Touring
2008 BRAKES On-Board Diagnostic (DSC/RSC) - Mazda CX-9
Repeat the inspection from Step 1.
If the malfunction occurs again, replace the DSC/RSC
Yes HU/CM, then go to the next step.
(See DSC/RSC HU/CM
REMOVAL/INSTALLATION .)
No
Go to the applicable DTC inspection.
Yes
(See ON-BOARD DIAGNOSTIC [DSC/RSC].)
No
Combined sensor system (CAN2 line malfunction)
The signal from the combined sensor is not within specification.
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)
Go to the next step.
DTC troubleshooting completed.