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Diagnostic Item 25: Diagnose the lines between the joint connectors (CAN1 and CAN2). <Vehicles with ACC>
 
 
cautionWhen servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted water pipe. If you fail to do, a component connected to the CAN bus line may be broken.
 
 
FUNCTION
The diagnostic result demonstrates that "diagnose the lines between the joint connectors (CAN1 and CAN2)" when the scan tool (M.U.T.-III) checks the periodically sent data from each ECU and cannot receive the engine control module (ECM) data.
 
 
TROUBLE JUDGMENT CONDITIONS
Scan tool (M.U.T.-III) judges the trouble when the periodically sent data from ECM cannot be received.
 
 
TROUBLESHOOTING HINTS
Damaged harness wires and connectors
 
 
DIAGNOSIS
STEP 1. Connector check: joint connector (CAN1) and joint connector (CAN2)
cautionThe strand end of the twist wire should be within 10 cm from the connector. For details refer to .
When checking the joint connector, ensure that its wiring harness side and its short pins are not damaged.
Is the check result normal?
Go to Step 2.
Repair the defective connector. Replace the joint connector as necessary.
 
STEP 2. Resistance measurement at joint connector (CAN1) and joint connector (CAN2).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect the joint connector (CAN1) and the joint connector (CAN2), and measure at the wiring harness side.
(2) Turn the ignition switch to the LOCK (OFF) position.
(3)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(4) Continuity between joint connector (CAN1) terminal No.8 and joint connector (CAN2) terminal No.11
OK: Continuity (2 ohms or less)
(5) Continuity between joint connector (CAN1) terminal No.17 and joint connector (CAN2) terminal No.22
OK: Continuity (2 ohms or less)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<All the resistances measure 2 ohms or less> Follow diagnosis item 21, 22, 23, 24, 26 and 27. Refer to .
: <Either or all of the resistances measure more than 2 ohms> Repair the wiring harness between joint connector (CAN1) and joint connector (CAN2).