How To Proceed With Troubleshooting [09/2015 - ]: Procedure

Result

Result:  1

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See step  2

Standard voltage

11 to 14 V

If the voltage is below 11 V, recharge or replace the battery before proceeding.

Result

Result:  1

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See step  3

1. Using the Techstream, check for all DTCs.
   NOTE:

   • If codes indicating internal or power source-related malfunctions of ECUs or sensors are output together with codes indicating that those ECUs or sensors cannot communicate via CAN communication, it is likely that the problem is not in the CAN communication line. Therefore, perform troubleshooting for the DTCs related to the malfunctioning parts first.
   • If a connector of a system which includes a CAN communication line is disconnected when the engine switch is on (IG) or on (ACC), CAN communication DTCs will be stored by that system and any related systems.

   Result

   Result
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Result:  1

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See step  4

1. Based on the vehicle equipment and specifications, confirm the systems that use CAN communication.

   Refer to DIAGNOSIS SYSTEM [09/2015 - ]

   Result

   Result
   NEXT

Result:  1

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See step  5

1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and CAN branch wire.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition	Proceed to
   L31-6 (CANH) - L31-14 (CANL)	Engine switch off	OK (54 to 69 Ω)	A
   L31-6 (CANH) - L31-14 (CANL)	Engine switch off	NG (Higher than 70 Ω)	B
   L31-6 (CANH) - L31-14 (CANL)	Engine switch off	NG (Below 53 Ω)	C

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of DLC3

Result:  2

B 

GO TO "Open in CAN Main Wire". Refer to  Open in CAN Main Wire [09/2015 - ] 

Result:  3

C 

GO TO "Short in CAN Bus Lines". Refer to  Short in CAN Bus Lines [09/2015 - ] 

Result:  1

A 

See step  6

1. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   L31-6 (CANH) - L31-16 (BAT)	Engine switch off	6 kΩ or higher
   L31-14 (CANL) - L31-16 (BAT)	Engine switch off	6 kΩ or higher

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of DLC3

   Result

   Result	Proceed to
   OK	A
   NG	B

Result:  2

B 

GO TO "Short to B+ in CAN Bus Lines". Refer to  Short to B+ in CAN Bus Line [09/2015 - ] 

Result:  1

A 

See step  7

1. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   L31-6 (CANH) - L31-4 (CG)	Engine switch off	200 Ω or higher
   L31-14 (CANL) - L31-4 (CG)	Engine switch off	200 Ω or higher

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of DLC3

   Result

   Result	Proceed to
   OK	A
   NG	B

Result:  2

B 

GO TO "Short to GND in CAN Bus Lines". Refer to  Short to GND in CAN Bus Line [09/2015 - ] 

Result:  1

A 

See step  8

1. Connect the cable to the negative (-) battery terminal.
   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

   Refer to INITIALIZATION [09/2015 - ]

2. Select "Bus Check" from "System Select".

   Refer to DIAGNOSIS SYSTEM [09/2015 - ]

3. Check the display of the connected ECUs and sensors for a minute.

   Result

   Inspection Result	Proceed to
   All ECUs and sensors connected to CAN communication system are displayed on screen (CAN bus circuit currently normal)	A
   Except for skid control ECU assembly, no ECUs connected to steering bus are displayed (steering bus CAN main wire open or short malfunction)	B
   No ECUs connected to steering bus are displayed (CAN branch wire between skid control ECU assembly and V bus circuit is open)	C
   Except for ECM, no ECUs connected to braking and driving bus are displayed (braking and driving bus CAN main wire open or short malfunction)	D
   No ECUs connected to braking and driving bus are displayed (CAN branch wire between ECM and V bus circuit is open)	E
   Except for main body ECU, no ECUs connected to MS bus are displayed (MS bus CAN main wire open or short malfunction)	F
   No ECUs connected to MS bus are displayed (CAN branch wire between main body ECU and V bus circuit is open)	G
   Except for driving support ECU assembly, no ECUs connected to parking assist bus are displayed (parking assist bus CAN main wire open or short malfunction)	H
   No ECUs connected to parking assist bus are displayed (CAN branch wire between driving support ECU assembly and MS bus, braking and driving bus and steering bus circuit is open)	I
   Except for network gateway ECU, no ECUs connected to V2 bus are displayed (V2 bus CAN main wire open or short malfunction)	J
   No ECUs connected to V2 bus are displayed (CAN branch wire between network gateway ECU and V bus circuit is open)	K
   Single ECU or sensor that should be connected to CAN communication is not displayed (ECU or sensor CAN branch wire open or communication stop)	L
   ECU or sensor that should be connected to CAN communication is not displayed or display is intermittent during check (ECU or sensor CAN branch wire open on one side)	M

   NOTE:

   ECUs and sensors that are not present will not be displayed. Be careful not to mistake them for communication stop malfunctions.

   HINT: 

   • If the display of an ECU is intermittent during the check, one side of an ECU or sensor CAN branch wire is open (the signal of the ECU is treated as noise, which affects the response and display of the Techstream).
   • The skid control ECU assembly checks for proper ECU communication for ECUs that are connected to the steering bus and the results are displayed on the Techstream. ECUs that stop communicating with the skid control ECU assembly for 3 seconds or more will stop being displayed on the Techstream.
   • The skid control ECU assembly may be malfunctioning if both of the following occur: 1) all ECUs connected to the steering bus are not displayed on the Techstream; and 2) DTC U1005 Lost Communication with Gateway Module is not output.
   • The ECM checks for proper ECU communication for ECUs that are connected to the braking and driving bus and the results are displayed on the Techstream. ECUs that stop communicating with the ECM for 3 seconds or more will stop being displayed on the Techstream.
   • The ECM may be malfunctioning if both of the following occur: 1) all ECUs connected to the braking and driving bus are not displayed on the Techstream; and 2) DTC U1004 Lost Communication with Gateway Module is not output.
   • The main body ECU checks for proper ECU communication for ECUs that are connected to the MS bus and the results are displayed on the Techstream. ECUs that stop communicating with the main body ECU for 10 seconds or more will stop being displayed on the Techstream.
   • The main body ECU may be malfunctioning if both of the following occur: 1) all ECUs connected to the MS bus are not displayed on the Techstream; and 2) DTC U1002 Lost Communication with Gateway Module (MS Bus) is not output.
   • The driving support ECU assembly checks for proper ECU communication for ECUs that are connected to the parking assist bus and the results are displayed on the Techstream. ECUs that stop communicating with the driving support ECU assembly for 10 seconds or more will stop being displayed on the Techstream.
   • The driving support ECU assembly may be malfunctioning if both of the following occur: 1) all ECUs connected to the parking assist bus are not displayed on the Techstream; and 2) DTC U1002 Lost Communication with Gateway Module (Parking Assist Bus) is not output.
   • The network gateway ECU checks for proper ECU communication for ECUs that are connected to the V2 bus and the results are displayed on the Techstream. ECUs that stop communicating with the network gateway ECU for 10 seconds or more will stop being displayed on the Techstream.
   • The network gateway ECU may be malfunctioning if both of the following occur: 1) all ECUs connected to the V2 bus are not displayed on the Techstream; and 2) DTC U1002 Lost Communication with Gateway Module (V2 Bus) is not output.

Result:  2

B 

GO TO "DTC U1005". Refer to  DTC U1005: Lost Communication with Electronically Controlled Brake Gateway Module [09/2015 - ] 

Result:  3

C 

GO TO "Skid Control ECU Communication Stop Mode". Refer to  Skid Control ECU Communication Stop Mode [09/2015 - ] 

Result:  4

D 

GO TO "DTC U1004". Refer to  DTC U1004: Lost Communication with Engine Gateway Module [09/2015 - ] 

Result:  5

E 

GO TO "ECM Communication Stop Mode". Refer to  ECM Communication Stop Mode [09/2015 - ] 

Result:  6

F 

GO TO "DTC U1002". Refer to  DTC U1002: Lost Communication with Gateway Module [09/2015 - ] 

Result:  7

G 

GO TO "Main Body ECU Communication Stop Mode". Refer to  Main Body ECU Communication Stop Mode [09/2015 - ] 

Result:  9

H 

GO TO "DTC U1002". Refer to  DTC U1002: Lost Communication with Gateway Module (Parking Assist Bus) [09/2015 - ] 

Result:  8

I 

GO TO "DTC U1101". Refer to  DTC U1101: Lost Communication with Driving Support ECU [09/2015 - ] 

Result:  10

J 

GO TO "DTC U1002". Refer to  DTC U1002: Lost Communication with Gateway Module (Network Gateway ECU) [09/2015 - ] 

Result:  11

K 

GO TO "Gateway ECU Communication Stop Mode". Refer to  Gateway ECU Communication Stop Mode [09/2015 - ] 

Result:  12

L 

GO TO "Problem Symptoms Table". Refer to  PROBLEM SYMPTOMS TABLE [09/2015 - ]  

Result:  13

M 

GO TO "Open in One Side of CAN Branch Line". Refer to  Open in One Side of CAN Branch Line [09/2015 - ] 

Result:  1

A 

See step  9

1. Select "Bus Check" from "System Select".

   Refer to DIAGNOSIS SYSTEM [09/2015 - ]

2. Write down all of the DTCs output from each ECU.

   HINT: 

   • If there are communication malfunction DTCs output but the Techstream "Bus Check - Communication Bus Check" screen displays all of the ECUs and sensors connected to the CAN communication system, the communication malfunction DTCs may be past malfunctions that are no longer present.
   • For V bus main wire malfunctions, DTCs for related ECUs are also output. Therefore, determine the malfunctioning area based on all of the DTCs that are output.
   • For steering bus malfunctions, DTCs are stored based on the detection of communication stop malfunctions and network malfunctions of ECUs that are connected by the skid control ECU assembly.
   • For braking and driving bus malfunctions, DTCs are stored based on the detection of communication stop malfunctions and network malfunctions of ECUs that are connected by the ECM.
   • For MS bus malfunctions, DTCs are stored based on the detection of communication stop malfunctions and network malfunctions of ECUs that are connected by the main body ECU.
   • For parking assist bus malfunctions, DTCs are stored based on the detection of communication stop malfunctions and network malfunctions of ECUs that are connected by the driving support ECU assembly.
   • For V2 bus malfunctions, DTCs are stored based on the detection of communication stop malfunctions and network malfunctions of ECUs that are connected by the network gateway ECU assembly.

   Result

   Inspection Result	Proceed to
   ECU connected to V bus outputs communication trouble code	A
   Skid control ECU assembly outputs network malfunction trouble code (U1005) (steering bus CAN main wire past malfunction)	B
   ECM outputs network malfunction trouble code (U1004) (braking and driving bus CAN main wire past malfunction)	C
   Main body ECU outputs network malfunction trouble code (U1002) (MS bus CAN main wire past malfunction)	D
   Driving support ECU assembly outputs network malfunction trouble code (U1002) (parking assist bus CAN main wire past malfunction)	E
   Network gateway ECU outputs network malfunction trouble code (U1002) (V2 bus CAN main wire past malfunction)	F
   Skid control ECU assembly outputs trouble code other than the network malfunction trouble code (U1005) (past malfunction of ECU or CAN branch wire connected to steering bus)	G
   ECM outputs trouble code other than network malfunction trouble code (U1004) (past malfunction of ECU or CAN branch wire connected to braking and driving bus)	G
   Main body ECU outputs trouble code other than network malfunction trouble code (U1002) (past malfunction of ECU or CAN branch wire connected to MS bus)	G
   Driving support ECU assembly outputs trouble code other than network malfunction trouble code (U1002) (past malfunction of ECU or CAN branch wire connected to parking assist bus)	G
   Network gateway ECU outputs trouble code other than network malfunction trouble code (U1002) (past malfunction of ECU or CAN branch wire connected to V2 bus)	G

Result:  2

B 

GO TO "DTC U1005". Refer to  DTC U1005: Lost Communication with Electronically Controlled Brake Gateway Module [09/2015 - ] 

Result:  6

C 

GO TO "DTC U1004". Refer to  DTC U1004: Lost Communication with Engine Gateway Module [09/2015 - ] 

Result:  4

D 

GO TO "DTC U1002". Refer to  DTC U1002: Lost Communication with Gateway Module [09/2015 - ] 

Result:  5

E 

GO TO "DTC U1002". Refer to  DTC U1002: Lost Communication with Gateway Module (Parking Assist Bus) [09/2015 - ] 

Result:  7

F 

GO TO "DTC U1002". Refer to  DTC U1002: Lost Communication with Gateway Module (Network Gateway ECU) [09/2015 - ] 

Result:  8

G 

GO TO "DIAGNOSTIC TROUBLE CODE CHART". Refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2015 - ] 

Result:  1

A 

See step  10

1. Based on the combination of output CAN communication system DTCs, determine which ECUs and sensors have a communication stop malfunction.

   Refer to DIAGNOSIS SYSTEM [09/2015 - ]

   Result

   Result
   NEXT

Result:  2

NEXT 

See step  11

1. Using the Techstream, clear all DTCs.
2. Perform a malfunction simulation test on all harnesses and connectors related to the V bus CAN main wire.
3. Check the DTCs that were output as a result of the malfunction simulation test. Then determine the malfunctioning area.

   Result

   Proceed to
   NEXT

Result:  1

NEXT 

See step  12

Result

Result:  1

NEXT 

See step  13

1. Using the Techstream, clear all DTCs.

   Result

   Proceed to
   NEXT

Result:  1

NEXT 

See step  14

Result

Result:  1

NEXT 

END