ON-BOARD DIAGNOSTIC FUNCTION [CAN (CONTROLLER AREA NETWORK)]

id094000104100

On-Board Diagnostic Function

Malfunction detection function

  • The failure detection function in each CAN system-related module detects malfunctions in input/output signals.
  • This function outputs the DTC for the detected malfunction to the DLC-2, and also sends the detected result to the memory function and fail-safe function.

Fail-safe function

  • When the failure detection function determines that there is a malfunction, the fail-safe function illuminates a warning light to inform the driver of the malfunction.

Memory function

  • The memory function stores the DTC for the malfunction of input/output signals for related parts, as determined by the failure detection function.

Self-malfunction diagnostic function

  • The self-malfunction diagnostic function determines that there is a malfunction, and outputs a signal, as a DTC, to the DLC-2. The DTC can be read out using the Mazda Modular Diagnostic System (M-MDS).

HS-CAN

DTC output module (M-MDS display) | DTC | Malfunction location
--- | --- | ---
PCM (PCM) | U0101 | Communication error to TCM
U0140 | Communication error to BCM
TCM (TCM) | U0073:00 | CAN system communication error
U0100:00 | Communication error to PCM
U0121:00 | Communication error to DSC/RSC HU/CM
U0155:00 | Communication error to instrument cluster
U0415:00 | Abnormal message from DSC/RSC HU/CM
DSC/RSC HU/CM (ABS) | U0073 | CAN system communication error
U0100 | Communication error to PCM
U0140 | Communication error to BCM
U0155 | Communication error to instrument cluster
BCM (GEM) | U0073 | CAN system communication error
U0100 | Communication error to PCM
U0101 | Communication error to TCM
U0121 | Communication error to DSC/RSC HU/CM
U0401 | Abnormal message from PCM
4WD control module*1 (4×4) | U0073 | CAN system communication error
U0100 | Communication error to PCM
U0101 | Communication error to TCM
U0121 | Communication error to DSC/RSC HU/CM
U0155 | Communication error to instrument cluster
Keyless control module*2 (RKE) | U0073 | CAN system communication error
U0100 | Communication error to PCM
U0140 | Communication error to BCM
U0323 | Communication error to instrument cluster
U2023 | Abnormal message from PCM
PLG control module*3 (LTM) | U0073 | CAN system communication error
U0100 | Communication error to PCM
U0101 | Communication error to TCM
U0140 | Communication error to BCM
U0155 | Communication error to instrument cluster
U0214 | Communication error to keyless control module
BSM control module (RH)*4 (BSMR) | U0001:88 | CAN system communication error
U0100:00 | Communication error to PCM
U0101:00 | Communication error to TCM
U0140:00 | Communication error to BCM
U0232:00 | Communication error to BSM control module (LH)
U0401:68 | Signal error from PCM
U0402:68 | Signal error from TCM
U0422:68 | Signal error from BCM
U0533:68 | Signal error from BSM control module (LH)
BSM control module (LH)*4 (BSML) | U0001:88 | CAN system communication error
U0100:00 | Communication error to PCM
U0101:00 | Communication error to TCM
U0140:00 | Communication error to BCM
U0233:00 | Communication error to BSM control module (RH)
U0401:68 | Signal error from PCM
U0402:68 | Signal error from TCM
U0422:68 | Signal error from BCM
U0534:68 | Signal error from BSM control module (RH)
Position memory control module*5 (DSM) | U0001:88 | CAN system communication error
U0100:00 | Communication error to PCM
U0101:00 | Communication error to TCM
U0121:00 | Communication error to DSC/RSC HU/CM
U0140:00 | Communication error to BCM
U0155:00 | Communication error to instrument cluster
U0431:68 | Abnormal message from BCM
SAS control module (RCM) | U0073 | CAN system communication error
U0155 | Communication error to instrument cluster
Theft-deterrent control module*6 (VSM) | U0001:88 | CAN system communication error
U0100:00 | Communication error to PCM
U0140:00 | Communication error to BCM
Forward sensing camera*7 (FSC) | U0001:88 | CAN system communication error
U0100:00 | Communication error to PCM
U0121:00 | Communication error to DSC/RSC HU/CM
U0140:00 | Communication error to BCM
U0155:00 | Communication error to instrument cluster
U0401:68 | Abnormal message from PCM
U0415:68 | Abnormal message from DSC/RSC HU/CM
U0422:68 | Abnormal message from BCM
U0423:68 | Abnormal message from instrument cluster
U2005:68 | Abnormal message from PCM
Instrument cluster (IC) | U0073 | CAN system communication error
U0100 | Communication error to PCM
U0101 | Communication error to TCM
U0114 | Communication error to 4WD control module
U0121 | Communication error to DSC/RSC HU/CM
U0140 | Communication error to BCM
U0151 | Communication error to SAS control module
U0200 | Communication error to BSM control module (RH)
U0214 | Communication error to keyless control module
U023A | Communication error to forward sensing camera
U2510 | Communication error to PCM

*1 :With 4WD
*2 :With advanced keyless entry and start system
*3 :With PLG system
*4 :With blind spot monitoring (BSM) control module connector 8-pin type
*5 :With memory power seat
*6 :With theft-deterrent system
*7 :With forward sensing camera

MS-CAN

DTC output module (M-MDS display) | DTC | Malfunction location
--- | --- | ---
Audio unit (ACU) | U0010:88 (16:Er12) | CAN system communication error
BSM control module (LH)*1 (BSML) | U0010:88 | CAN system communication error
U0100:00 | Communication error to PCM
U0140:00 | Communication error to BCM
Information display*2 | 01:Er | CAN system communication error
02:1E | Communication error to audio unit
02:3E | Communication error to instrument cluster
Information display*3 | 01Er | CAN system communication error
02 1E | Communication error to audio unit
02 3E | Communication error to instrument cluster

*1 :With blind spot monitoring (BSM) control module connector 10-pin type
*2 :With clock display
*3 :Without clock display

Narrowing down malfunction locations

• When the CAN system is thought to be malfunctioning based on the repair order form and the malfunctioning symptom, perform the CAN system on-board diagnosis.
• DTCs are output due to a control module or sensor malfunction, or incorrect power supply. Verify the output DTCs and first inspect the DTCs not shown in the DTC table.
• The open circuit location in the CAN system can be determined by verifying the DTCs detected in each module and by the module which has failed.
• It is possible for signal error DTCs to be output in addition to communication error DTCs if there is an open circuit. Determine the open circuit location if the communication error and signal error DTCs are output simultaneously.
• For DTC details, refer to the “Self-malfunction diagnostic function”. (See Self-malfunction diagnostic function.)

Troubleshooting procedure

ac9wzn00000828

Example: DSC/RSC HU/CM-related wiring harness open circuit (if DTC is output)

1. Verify the CAN system-related module DTCs and the failed module using the Mazda Modular Diagnostic System (M-MDS).

Module | Displayed DTC | Probable malfunction location
--- | --- | ---
TCM (TCM) | U0121 | Communication error to DSC/RSC HU/CM
GEM (BCM) | U0121 | Communication error to DSC/RSC HU/CM
4X4 (4WD control module) | U0121 | Communication error to DSC/RSC HU/CM
DSM (position memory control module) | U0121:00 | Communication error to DSC/RSC HU/CM
FSC (forward sensing camera) | U0121:00 | Communication error to DSC/RSC HU/CM
IC (instrument cluster) | U0121 | Communication error to DSC/RSC HU/CM

Module | Fail
--- | ---
ABS (DSC/RSC HU/CM) | ×

ac9wzn00000820

2. Despite normal communication between the PCM and instrument cluster, a communication error DTC is displayed for the signal between the DSC/RSC HU/CM and TCM/ BCM/ 4WD control module/ position memory control module/ forward sensing camera/ instrument cluster. In addition, the wiring harness between the DSC HU/CM and connector C-36 is considered to be malfunctioning because “Fail” is displayed for the DSC/RSC HU/CM.