Operation CHARM: Car repair manuals for everyone.
Home >> Toyota Truck >> 2008 >> Highlander 4WD V6-3.3L (3MZ-FE) Hybrid >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Information Bus >> Testing and Inspection >> Initial Inspection and Diagnostic Overview >> CAN Communication System >> How to Proceed With Troubleshooting

How to Proceed With Troubleshooting








CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING

HOW TO PROCEED WITH TROUBLESHOOTING
NOTICE:
- DTCs for the CAN communication system are as follows: U0073, U0100, U0100-211, U0100-212, U0100-530, U0100-774, U0100-784, U0123, U0124, U0126, U0127, U0129, U0129-220, U0129-222, U0129-528, U0129-529, U0140-146, U0164-827, U0230*1, U0293, U0327, U1002, B1499 and C2179.
*1: w/ Power back door system
- Refer to troubleshooting of each system if DTCs regarding the CAN communication system are not output.

1. INSPECT BATTERY VOLTAGE
Standard voltage:
11 to 14 V
HINT: If the voltage is below 11 V, recharge or replace the battery before proceeding.

NEXT -- Continue to next step.
2. CHECK AND CLEAR DTCS
HINT:
- CAN communication DTCs are output when there is an open or short in any of the communication wires. Any problems with the power source of a corresponding ECU or sensor, or problems in the ECU, the sensor itself also cause these DTCs to be output.
- If a CAN communication wire connector is disconnected with the power switch on (IG), the ECUs of the corresponding system and related systems record a DTC.

NEXT -- Continue to next step.
3. CHECK INSTALLED SYSTEMS (ECU AND SENSOR) THAT USE CAN COMMUNICATION
(a) Based on the vehicle equipment and specifications, confirm the systems that use CAN communication Diagnosis System.
NEXT -- Continue to next step.
4. CHECK DLC3 BRANCH WIRE AND CAN NO. 1 BUS CIRCUIT MAIN WIRE (CANH - CANL)
NOTICE:
- Turn the power switch off before measuring the resistances of the CAN main wire and the CAN branch wire.
- After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
- Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors. If the doors need to be opened in order to check the connectors, open the doors and leave them open.
HINT: Operating the power switch, any other switches, or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
(a) Turn the power switch off.





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






B -- GO TO CAN MAIN WIRE FOR DISCONNECTION
C -- GO TO CHECK CAN BUS LINES FOR SHORT CIRCUIT
A -- Continue to next step.
5. CHECK FOR SHORT TO GND IN CAN NO. 1 BUS (CANH, CANL - CG)
(a) Turn the power switch off.





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- GO TO CHECK CAN BUS LINE FOR SHORT TO GND
OK -- Continue to next step.
6. CHECK FOR SHORT TO +B IN CAN NO. 1 BUS (CANH, CANL - BAT)
(a) Disconnect the negative battery terminal.





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- GO TO CHECK CAN BUS LINE FOR SHORT TO +B
OK -- Continue to next step.
7. CHECK TECHSTREAM
(a) Using the Techstream, select "CAN Bus Check" from the "System Select".
(b) Observe the screen for approximately 1 minute to check the ECUs and sensors displayed on the screen.
Result:





NOTICE:
- The systems (ECUs, sensors) that adopt CAN communication vary depending on the vehicle and optional equipment. Check which systems (ECUs, sensors) are installed on the vehicle Diagnosis System.
- Non-installed ECUs or sensors will not be displayed. Do not mistake them for being in the communication stop mode.
- The ECUs and sensors that repeatedly appear and disappear from the screen during this check are considered normal. (The response to Techstream and the Techstream display are affected by signals output from other ECUs which have an open circuit in either of their CAN branch wires.)
HINT:
- (*1): See "DTC CHART" instead of the "COMMUNICATION STOP MODE TABLE" when some of the ECUs connected to the CAN MS bus are not displayed on the screen Diagnosis System.
- The ECUs connected to the CAN MS bus are displayed on the screen by the main body ECU.

B -- GO TO "COMMUNICATION STOP MODE TABLE"
C -- GO TO "OPEN IN ONE SIDE OF CAN BRANCH WIRE"
D -- GO TO "U1002 (CAN MS BUS)"
E -- GO TO "MAIN BODY ECU COMMUNICATION STOP MODE"
A -- Continue to next step.
8. RECHECK DTC
HINT:
- Sometimes CAN communication system DTCs are output, but all the ECUs and sensors connected to the CAN communication system are displayed on the Techstream. In this case, previous or history DTCs may indicate the cause of the problem.
- ECUs related to a problem in the CAN bus will store DTCs to indicate communication malfunctions. The communication stop mode in the CAN bus can be determined by comparing the combination of DTCs that have been set. Refer to the DTC combination table for the CAN bus.
- The main body ECU will store communication error DTCs when the ECUs connected to the CAN MS bus cannot communicate, or if a network malfunction occurs.

Result:






B -- GO TO "U1002 (CAN MS BUS)"
C -- GO TO "DTC CHART"
A -- Continue to next step.
9. DTC COMBINATION TABLE
(a) Confirm trouble according to the combination of output DTCs regarding the CAN communication system Diagnosis System.
HINT: Previous CAN communication system DTCs may be the cause if CAN communication system DTCs are output and all ECUs and sensors connected to the CAN communication system are displayed on the Techstream's "CAN Bus Check" screen.

NEXT -- Continue to next step.
10. CIRCUIT INSPECTION
NEXT -- Continue to next step.
11. IDENTIFICATION OF PROBLEM
NEXT -- Continue to next step.
12. REPAIR OR REPLACE
NEXT -- Continue to next step.
13. CONFIRMATION TEST
NEXT -- END
pro multis · About Operation CHARM