CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [SKYACTIV-G 2.0/2.5, SKYACTIV-D 2.2 (MTX) (L.H.D.)]
id100238000100
CAN malfunction diagnosis flow
Flowchart
 am6zzw00015276 
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Diagnostic procedure
| 
 Step  | 
 Inspection  | 
 Action  | 
|
|---|---|---|---|
| 
 1 
 | 
 INSPECT IF COMMUNICATION BETWEEN M-MDS AND PCM IS POSSIBLE 
•  Connect the M-MDS to the DLC-2. 
•  Switch the ignition ON (engine off). 
•  Perform vehicle identification. 
•  Can the vehicle be identified? 
 | 
 Yes 
 | 
 Go to the next step. 
 | 
| 
 No 
 | 
 Go to Step 5 as a malfunction in the HS-CAN circuit has occurred. 
 | 
||
| 
 2 
 | 
 INSPECT MODULE FOR INABILITY TO COMMUNICATE DUE TO CAN MALFUNCTION 
•  Implement the network test using the M-MDS.
 
•  Is there a module indicating a malfunction? 
 | 
 Yes 
 | 
 Go to Step 12 as a malfunction in the CAN circuit has occurred. 
 | 
| 
 No 
 | 
 Go to the next step. 
 | 
||
| 
 3 
 | 
 INSPECT FOR SHORT TO POWER SUPPLY IN CAN_H SIDE OF MS-CAN OR HS-CAN 
•  Measure the voltage between the following terminals: 
 •  Is B+ voltage measured between any of the terminals? 
  | 
 Yes 
 | 
 A short to power supply in the CAN_H side of MS-CAN or HS-CAN. 
Determine the location of the short to power supply according to the diagnosis procedure for determining the location of a short to power supply. 
 | 
| 
 No 
 | 
 Go to the next step. 
 | 
||
| 
 4 
 | 
 INSPECT FOR SHORT TO GROUND IN CAN_L SIDE OF HS-CAN OR MS-CAN 
•  Measure the voltage between the following terminals: 
 •  Is the voltage measured as 0 V? 
 | 
 Yes 
 | 
 A short to ground on the CAN_L side of the HS-CAN or MS-CAN has occurred. 
Determine the location of the short to ground according to the diagnosis procedure for determining the location of a short to ground. 
 | 
| 
 No 
 | 
 The current CAN circuit is normal, return to FOREWARD, and go to the next step of the CAN malfunction diagnosis in the troubleshooting procedure. 
 | 
||
| 
 5 
 | 
 VERIFY IF PUSH BUTTON START SYSTEM HAS MALFUNCTION 
•  Switch the ignition ON (engine off). 
•  Can the ignition be switched ON? 
 | 
 Yes 
 | 
 Go to the next step. 
 | 
| 
 No 
 | 
 A malfunction in the push button start system has occurred. 
Perform diagnosis according to the symptom troubleshooting. 
 | 
||
| 
 6 
 | 
 INSPECT FOR MALFUNCTION IN M-MDS 
•  Connect the M-MDS to a normal vehicle and implement vehicle identification. 
•  Can the vehicle be identified? 
 | 
 Yes 
 | 
 Go to the next step. 
 | 
| 
 No 
 | 
 A malfunction in the M-MDS can be considered. 
Repair the M-MDS. 
 | 
||
| 
 7 
 | 
 INSPECT HS-CAN FOR SHORT TO POWER SUPPLY 
•  Measure the voltage between the following terminals: 
 •  Is B+ voltage measured between any of the terminals? 
  | 
 Yes 
 | 
 A short to power supply in the CAN_H side or CAN_L of HS-CAN has occurred. 
Determine the location of the short to power supply according to the diagnosis procedure for determining the location of a short to power supply. 
 | 
| 
 No 
 | 
 Go to the next step. 
 | 
||
| 
 8 
 | 
 INSPECT HS-CAN FOR OPEN CIRCUIT 
•  Measure the voltage between the following terminals: 
 •  Is the voltage between both terminals (CAN_H side and CAN_L side) equal? 
 | 
 Yes 
 | 
 Go to Step 11 as a short to ground or a short between circuits has occurred in the HS-CAN. 
 | 
| 
 No 
 | 
 Go to the next step. 
 | 
||
| 
 9 
 | 
 DETERMINE IF OPEN CIRCUIT LOCATION IN HS-CAN CIRCUIT IS BETWEEN DLC AND CONNECTOR C-34 OR ELSEWHERE 
•  Start the engine to verify that the immobilizer system operates normally. 
•  Can the engine be started? 
  | 
 Yes 
 | 
 Go to the next step. 
 | 
| 
 No 
 | 
 An open circuit has occurred between the PCM and connector C-34 in the HS-CAN. 
Determine the location of the open circuit according to the diagnosis procedure for determining the location of an open circuit. 
 | 
||
| 
 10 
 | 
 DETERMINE IF OPEN CIRCUIT LOCATION IN HS-CAN CIRCUIT IS BETWEEN DLC AND CONNECTOR C-34 OR ELSEWHERE 
•  Switch the ignition ON (engine off). 
•  Verify if the check engine light in the instrument cluster illuminates. 
•  Start the engine. 
•  Verify if the check engine light turns off. 
•  Does the check engine light turn off? 
 | 
 Yes 
 | 
 An open circuit between DLC-2 and connector C-34 has occurred. 
Repair or replace the wiring harness for an open circuit, then return to Step 1. 
 | 
| 
 No 
 | 
 An open circuit has occurred between the PCM and connector C-34 in the HS-CAN. 
Determine the location of the open circuit according to the diagnosis procedure for determining the location of an open circuit. 
 | 
||
| 
 11 
 | 
 VERIFY MALFUNCTION OCCURRED IN HS-CAN CIRCUIT 
•  Measure the voltage between the following terminals: 
 •  Is the voltage between both terminals (CAN_H side and CAN_L side) 0 V? 
 | 
 Yes 
 | 
 A short to ground in CAN_H side of HS-CAN has occurred. 
Determine the location of the short to ground according to the diagnosis procedure for determining the location of a short to ground. 
 | 
| 
 No 
 | 
 A short between circuits in the CAN_H side and the CAN_L side of HS-CAN has occurred. 
Determine the location of the short between circuits according to the diagnosis procedure for determining the location of a short between circuits. 
 | 
||
| 
 12 
 | 
 DETERMINE CAN COMMUNICATION SPECIFICATION IN WHICH MALFUNCTION OCCURS 
•  Refer to the CAN communication specification quick reference table and verify the CAN communication specification (HS-CAN or MS-CAN) that is connected to the module which is indicating a malfunction.
 
•  Is the module that is indicating a malfunction HS-CAN? 
 | 
 Yes 
 | 
 An open circuit in the HS-CAN has occurred. 
Determine the location of the open circuit according to the diagnosis procedure for determining the location of an open circuit. 
 | 
| 
 No 
 | 
 Go to the next step. 
 | 
||
| 
 13 
 | 
 INSPECT CAN_L SIDE OF MS-CAN FOR SHORT TO POWER SUPPLY 
•  Measure voltage between DLC-2 terminal K (CAN_L side) and body ground. 
•  Can B+ voltage be measured? 
  | 
 Yes 
 | 
 A short to power supply in the CAN_L side of the MS-CAN has occurred. 
Determine the location of the short to power supply according to the diagnosis procedure for determining the location of a short to power supply. 
 | 
| 
 No 
 | 
 Go to the next step. 
 | 
||
| 
 14 
 | 
 INSPECT MS-CAN FOR OPEN CIRCUIT 
•  Measure the voltage between the following terminals: 
 •  Is the voltage between both terminals (CAN_H side and CAN_L side) equal? 
 | 
 Yes 
 | 
 Go to the next step. 
 | 
| 
 No 
 | 
 Open circuit in MS-CAN has occurred. 
Determine the location of the open circuit according to the diagnosis procedure for determining the location of an open circuit. 
 | 
||
| 
 15 
 | 
 VERIFY MALFUNCTION OCCURRED IN MS-CAN 
•  Measure the voltage between the following terminals: 
 •  Is the voltage between both terminals (CAN_H side and CAN_L side) 0 V? 
 | 
 Yes 
 | 
 A short to ground in the CAN_H side of the MS-CAN has occurred. 
Determine the location of the short to ground according to the diagnosis procedure for determining the location of a short to ground. 
 | 
| 
 No 
 | 
 A short between circuits on the CAN_H side and CAN_L side of MS-CAN has occurred. 
Determine the location of the short between circuits according to the diagnosis procedure for determining the location of a short between circuits. 
 | 
||
CAN communication specification quick reference table
| 
 CAN communication related module (M-MDS display)  | 
 CAN communication specification  | 
|
|---|---|---|
| 
 HS-CAN  | 
 MS-CAN  | 
|
| 
 PCM 
(PCM) 
 | 
 × 
 | 
 | 
| 
 DSC HU/CM 
(ABS) 
 | 
 × 
 | 
 | 
| 
 Radar unit 
(SBS/MRCC) 
 | 
 × 
 | 
 | 
| 
 TCM 
(TCM) 
 | 
 × 
 | 
 | 
| 
 Front body control module (FBCM) 
(F_BCM) 
 | 
 × 
 | 
 | 
| 
 Adaptive front lighting system (AFS) control module / auto leveling control module 
(AFS) 
 | 
 × 
 | 
 | 
| 
 DC-DC converter (i-ELOOP) 
(DCDC) 
 | 
 × 
 | 
 | 
| 
 4WD control module 
(4×4) 
 | 
 × 
 | 
 | 
| 
 Electric parking brake control module 
(EPB) 
 | 
 × 
 | 
 | 
| 
 Position memory control module 
(DSM) 
 | 
 × 
 | 
 | 
| 
 Audio amplifier 
(AM) 
 | 
 × 
 | 
 | 
| 
 Forward sensing camera (FSC) 
(FSC) 
 | 
 × 
 | 
 | 
| 
 EPS control module 
(EPS) 
 | 
 × 
 | 
 | 
| 
 MAZDA ERA-GLONASS control module 
(DCM) 
 | 
 × 
 | 
 | 
| 
 Start stop unit 
(SSU) 
 | 
 × 
 | 
 | 
| 
 Connectivity master unit (CMU) 
(CMU) 
 | 
 × 
 | 
 | 
| 
 SAS control module 
(RCM) 
 | 
 × 
 | 
 | 
| 
 Instrument cluster 
(IC) 
 | 
 × 
 | 
 | 
| 
 Climate control unit 
(EATC) 
 | 
 | 
 × 
 | 
| 
 Parking assist unit 
(PSM) 
 | 
 | 
 × 
 | 
| 
 Blind spot monitoring (BSM) control module (LH) 
(BSML) 
 | 
 | 
 × 
 | 
| 
 Rear mount camera 
 | 
 | 
 × 
 | 
| 
 Rear body control module (RBCM) 
(R_BCM) 
 | 
 | 
 × 
 | 
HS-CAN signal waveform
| 
 CAN circuit condition  | 
 Signal waveform (reference)  | 
|---|---|
| 
 Normal 
 | 
![]()  | 
| 
 •  CAN_H 
 •  CAN_L 
  | 
MS-CAN signal waveform
| 
 CAN circuit condition  | 
 Signal waveform (reference)  | 
|---|---|
| 
 Normal 
 | 
![]()  | 
| 
 •  CAN_H 
 •  CAN_L 
  |