Can Communication System (For Rhd Without Entry And Start System) How To Proceed With Troubleshooting
IMPORTANT POINTS CONCERNING TROUBLESHOOTING
VEHICLE BROUGHT TO WORKSHOP
INSPECT BATTERY VOLTAGE
CHECK FOR DTC*
CHECK INSTALLED SYSTEMS (ECU AND SENSOR) THAT USE CAN COMMUNICATION
CHECK FOR OPEN CIRCUIT IN DLC3 BRANCH WIRE AND V1 BUS CIRCUIT CAN MAIN WIRE AND SHORT CIRCUIT (CANH - CANL)
CHECK FOR SHORT TO B+ IN CAN V1 BUS (CANH, CANL - BAT)
CHECK FOR SHORT TO GND IN CAN V1 BUS (CANH, CANL - CG)
CHECK ECUS CONNECTED TO CAN BUS*
CHECK COMMUNICATION MALFUNCTION DTC (PAST DTC CHECK)*
CHECK DTC COMBINATION TABLE (V1 BUS CAN BRANCH WIRE OPEN, PAST COMMUNICATION STOP MALFUNCTION)
PERFORM MALFUNCTION SIMULATION TEST (V1 BUS CIRCUIT CAN MAIN WIRE PAST MALFUNCTION)*
ADJUST, REPAIR AND REPLACE
CLEAR DTC*
CONFIRMATION TEST
Can Communication System (For Rhd Without Entry And Start System) -- How To Proceed With Troubleshooting |
IMPORTANT POINTS CONCERNING TROUBLESHOOTING |
- CAUTION:
- Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the airbag system.
- NOTICE:
- Refer to the troubleshooting procedures of each system if DTCs regarding the CAN communication system are not output.
- Before measuring the resistance, leave the vehicle for at least 1 minute and do not operate the ignition switch, any switches or any doors. If doors need to be opened in order to check connectors, open the doors and leave them open.
- After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work (LandCruiser RM000003YMD00TX.html).
- When disconnecting the cable, some systems need to be initialized after the cable is reconnected (LandCruiser RM000003YMF011X.html).
- HINT:
- Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
- *: Use the intelligent tester.
DTCs indicating a CAN communication malfunction are also stored due to internal or power source-related problems in ECUs or sensors of systems using CAN communication. Therefore, check whether codes indicating internal or power source-related problems in those systems are output together with the CAN communication DTCs.
It is possible to inspect the circuit of the DLC3 CAN branch wire or V1 bus CAN main wire for malfunctions by inspecting the terminals of the DLC3 using SST.
- NOTICE:
- It is only possible to inspect CAN branch wires to ECUs (sensors) or the V1 bus from the DLC3.
It is possible to check which ECUs (sensors) are not able to communicate via CAN communication by checking the "Bus Check" function of the intelligent tester (when the DLC3 CAN branch wire and V1 bus CAN main wire are normal).
- HINT:
- When checking "Bus Check", ECUs (sensors) whose CAN branch wire is open or that cannot communicate via CAN communication do not respond to the intelligent tester (they are not displayed on the screen).
- When checking "Bus Check", if a DTC indicating a CAN communication malfunction is output even though all ECUs (sensors) respond (they are displayed on the screen), use the DTC combination table to determine the suspected trouble area and perform symptom simulation.
For past malfunctions of the V1 bus, the ECUs (sensors) which cannot communicate via CAN communication can be determined from the combination of CAN communication DTCs that are output.
The network gateway ECU detects malfunctions in the V2 bus circuit and stores DTCs depending on the malfunctioning areas. The ECUs (sensors) which cannot communicate via CAN communication can be determined from the combination of CAN communication DTCs that are output.
When an open circuit malfunction is confirmed, before disconnecting the connectors for inspection, check whether the connectors are loose by pushing in the connector case.
When a connector is disconnected, check if the connector terminals or case is damaged, deformed, deteriorated, etc.
1.VEHICLE BROUGHT TO WORKSHOP |
2.INSPECT BATTERY VOLTAGE |
- Standard voltage:
- 11 to 14 V
If the voltage is below 11 V, recharge or replace the battery before proceeding.
Using the intelligent tester, check for all DTCs.
- NOTICE:
- 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 ignition switch is ON or ACC, CAN communication DTCs will be stored by that system and any related systems.
4.CHECK INSTALLED SYSTEMS (ECU AND SENSOR) THAT USE CAN COMMUNICATION |
Based on the vehicle equipment and specifications, confirm the systems that use CAN communication (LandCruiser RM000000WIB0EFX.html).
5.CHECK FOR OPEN CIRCUIT IN DLC3 BRANCH WIRE AND V1 BUS CIRCUIT CAN MAIN WIRE AND SHORT CIRCUIT (CANH - CANL) |
Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and CAN branch wire.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Switch Condition
| Specified Condition
| Proceed to
|
G48-6 (CANH) - G48-14 (CANL)
| Ignition switch off
| OK (54 to 69 Ω)
| A
|
G48-6 (CANH) - G48-14 (CANL)
| Ignition switch off
| NG (Higher than 70 Ω)
| B
|
G48-6 (CANH) - G48-14 (CANL)
| Ignition switch off
| NG (Below 53 Ω)
| C
|
Text in Illustration*a
| Front view of DLC3
|
6.CHECK FOR SHORT TO B+ IN CAN V1 BUS (CANH, CANL - BAT) |
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Switch Condition
| Specified Condition
|
G48-6 (CANH) - G48-16 (BAT)
| Ignition switch off
| 6 kΩ or higher
|
G48-14 (CANL) - G48-16 (BAT)
| Ignition switch off
| 6 kΩ or higher
|
Text in Illustration*a
| Front view of DLC3
|
7.CHECK FOR SHORT TO GND IN CAN V1 BUS (CANH, CANL - CG) |
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Switch Condition
| Specified Condition
|
G48-6 (CANH) - G48-4 (CG)
| Ignition switch off
| 200 Ω or higher
|
G48-14 (CANL) - G48-4 (CG)
| Ignition switch off
| 200 Ω or higher
|
Text in Illustration*a
| Front view of DLC3
|
8.CHECK ECUS CONNECTED TO CAN BUS* |
Connect the cable to the negative (-) battery terminal.
- NOTICE:
- When disconnecting the cable, some systems need to be initialized after the cable is reconnected (LandCruiser RM000003YMF011X.html).
Select "Bus Check" from "System Select" (LandCruiser RM000000WIB0EFX.html).
Check the display of the connected ECUs and sensors for a minute.
ResultInspection Result
| Proceed to
|
All ECUs and sensors connected to CAN communication system are displayed on screen (CAN bus circuit currently normal).
| A
|
Except for network gateway ECU, no ECUs connected to V2 bus are displayed (V2 bus CAN main wire open or short malfunction).
| B
|
No ECUs connected to V2 bus are displayed (CAN branch wire between network gateway ECU and V1 bus circuit is open).
| C
|
Single ECU or sensor that should be connected to CAN communication is not displayed (ECU or sensor CAN branch wire open or communication stop).
| D
|
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).
| E
|
- NOTICE:
- 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 intelligent tester).
- The network gateway ECU checks for proper ECU communication for ECUs that are connected to the steering bus and the results are displayed on the intelligent tester. ECUs that stop communicating with the network gateway ECU for 3 seconds or more will stop being displayed on the intelligent tester.
- The network gateway ECU may be malfunctioning if both of the following occur: 1) all ECUs connected to the steering bus are not displayed on the intelligent tester; and 2) DTC U1002 Lost Communication with Gateway Module is not output.
9.CHECK COMMUNICATION MALFUNCTION DTC (PAST DTC CHECK)* |
Select "Bus Check" from "System Select" (LandCruiser RM000000WIB0EFX.html).
Write down all of the DTCs output from each ECU.
- HINT:
- If there are communication malfunction DTCs output but the intelligent tester "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 V1 bus CAN 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 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.
ResultInspection Result
| Proceed to
|
ECU connected to V1 bus outputs communication trouble code.
| A
|
Network gateway ECU outputs network malfunction trouble code (U1002). (V2 bus CAN main wire past malfunction)
| B
|
Network gateway ECU outputs trouble code other than the network malfunction trouble code (U1002). (past malfunction of ECU or CAN branch wire connected to V2 bus)
| C
|
10.CHECK DTC COMBINATION TABLE (V1 BUS CAN BRANCH WIRE OPEN, PAST COMMUNICATION STOP MALFUNCTION) |
Based on the combination of output CAN communication system DTCs, determine which ECUs and sensors have a communication stop malfunction (LandCruiser RM000000WIB0EFX.html).
11.PERFORM MALFUNCTION SIMULATION TEST (V1 BUS CIRCUIT CAN MAIN WIRE PAST MALFUNCTION)* |
Using the intelligent tester, clear all DTCs.
Perform a malfunction simulation test on all harnesses and connectors related to the V1 bus CAN main wire.
Check the DTCs that were output as a result of the malfunction simulation test. Then determine the malfunctioning area.
12.ADJUST, REPAIR AND REPLACE |
Using the intelligent tester, clear all DTCs.