Up to 08/2009
NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING
NOTICE:
* DTCs for the CAN communication system are as follows: U0073, U0100, U0101, U0104, U0114, U0122, U0123, U0124, U0126, U0129, U0131, U0132, U0140, U0142, U0149, U0151, U0155, U0163, U0164, U0182, U0199, U0200, U0208, U0230, U0235, U0327, U1000, U1002, U1100, U1101, U1102, U1104, U1105, U1110, U110B, U1115, U1126, U1121, U1132 and U1133.
* Refer to troubleshooting of each system if DTCs regarding the CAN communication system are not output.
HINT
*: Use the Techstream.
1. VEHICLE BROUGHT TO WORKSHOP
NEXT -- Continue to next step.
2. CUSTOMER PROBLEM ANALYSIS
(a) Interview the customer and confirm the problem.
NEXT -- Continue to next step.
3. CHECK BATTERY
Standard Voltage:
11 to 14 V
HINT
If the voltage is below 11 V, recharge or replace the battery before proceeding to the next step.
NEXT -- Continue to next step.
4. CHECK AND CLEAR DTCS*
HINT
* CAN communication DTCs are stored 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 or the sensor itself also cause these DTCs to be stored.
* If a CAN communication wire connector is disconnected with the engine switch on (IG), the ECUs of the corresponding system and related systems store a DTC.
NEXT -- Continue to next step.
5. CHECK DLC3 BRANCH WIRE AND CAN NO. 1 BUS MAIN WIRE (CANH - CANL)
NOTICE:
* Turn the engine switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
* Turn the engine switch off before inspecting CAN bus wires for a ground short.
* After the engine switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
* Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.
HINT
* Operating the engine 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.
* Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.
(a) Turn the engine switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
Result:
B -- GO TO OPEN IN CAN MAIN BUS WIRE Open in CAN Main Bus Line
C -- GO TO SHORT IN CAN BUS LINES Check CAN Bus Lines for Short Circuit
A -- Continue to next step.
6. CHECK FOR SHORT TO GND IN CAN NO. 1 BUS (CANH, CANL - CG)
(a) Turn the engine switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- GO TO SHORT TO GND IN CAN BUS LINE Check CAN Bus Line for Short to GND
OK -- Continue to next step.
7. CHECK FOR SHORT TO +B IN CAN NO. 1 BUS (CANH, CANL - BAT)
(a) Disconnect the cable from the negative (-) battery terminal.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- GO TO SHORT TO +B IN CAN BUS LINE Check CAN Bus Line for Short To +B
OK -- Continue to next step.
8. 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.
9. CHECK ECUS CONNECTED TO CAN BUS*
(a) Select "CAN Bus Check" from screen on the Techstream Diagnosis System.
(b) Observe the screen for approximately 1 minute to check the ECUs and sensors displayed on the screen.
Result:
NOTICE:
* The systems (ECUs and sensors) that adopt CAN communication vary depending on the vehicle and optional equipment. Check which systems (ECUs and 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 the Techstream and its display are affected by signals output from other ECUs which have an open circuit in either of their CAN bus branch wires.)
HINT
* *1: See Diagnostic Trouble Code Chart instead of Communication Stop Mode Table when some of the ECUs connected to the CAN MS bus, the CAN No. 2 bus and power management bus are not displayed on the screen CAN Communication System.
* The ECUs connected to the CAN MS bus are displayed on the screen by the main body ECU.
* The ECUs connected to the CAN No. 2 bus are displayed on the screen by the power management control ECU.
B -- GO TO U1002 (MAIN BODY) U1002
C -- GO TO MAIN BODY ECU COMMUNICATION STOP MODE Main Body ECU Communication Stop Mode
D -- GO TO U1002 (POWER MANAGEMENT1) U1002
E -- GO TO U1002 (POWER MANAGEMENT2) U1002
F -- GO TO POWER MANAGEMENT CONTROL ECU COMMUNICATION STOP MODE Power Management Control ECU Communication Stop Mode
G -- GO TO COMMUNICATION STOP MODE TABLE Problem Symptoms Table
H -- GO TO OPEN IN ONE SIDE OF CAN BRANCH LINE Open in One Side of CAN Branch Line
A -- Continue to next step.
10. RECHECK DTC
HINT
* Sometimes CAN communication system DTCs are output, but all 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 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.
* The power management control ECU will store communication error DTCs when the ECUs connected to the CAN No. 2 bus and power management bus cannot communicate, or if a network malfunction occurs.
Result:
B -- GO TO U1002 (MAIN BODY) U1002
C -- GO TO U1002 (POWER MANAGEMENT1) U1002
D -- GO TO U1002 (POWER MANAGEMENT2) U1002
E -- GO TO DIAGNOSTIC TROUBLE CODE CHART CAN Communication System
A -- Continue to next step.
11. 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 "CAN Bus Check" of the Techstream.
NEXT -- Continue to next step.
12. CIRCUIT INSPECTION
NEXT -- Continue to next step.
13. IDENTIFICATION OF PROBLEM
NEXT -- Continue to next step.
14. REPAIR OR REPLACEMENT
NEXT -- Continue to next step.
15. CONFIRMATION TEST*
NEXT -- END