Diagnosis Item 4: Diagnose the terminator resistors


caution When servicing a CAN bus line, earth 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



TROUBLE JUDGEMENT




  • The M.U.T.-III can receive the periodic transmission data from all ECUs.
  • The voltage between CAN bus lines (CAN_L and CAN_H lines) is 1.0 V or more, 4.0 V or less.
  • The resistance at CAN bus line (CAN_L and CAN_H lines) is between 50 Ω and 70 Ω.

PROBABLE CAUSES



  • Damaged harness wires and connectors
  • Malfunction of the ETACS-ECU
  • Malfunction of the EV-ECU

DIAGNOSIS PROCEDURE

STEP 1. Resistance measurement at B-317 ETACS-ECU connector.
caution A digital multimeter should be used. For details refer to .
(1)Remove the ETACS-ECU, and measure at the equipment side.

(2)Resistance at B-317 ETACS-ECU connector terminal Nos.56 and 65
OK: 120 ± 20 Ω

Q. Is the check result normal?

<Within 120 ± 20 Ω> Go to Step 2.

<Not within 120 ± 20 Ω> Replace the ETACS-ECU and register the ID codes (Refer to GROUP 54A, Immobilizer system - On-vehicles service ).

STEP 2. Resistance measurement at C-108 EV-ECU connector.
caution A digital multimeter should be used. For details refer to .
(1)Remove the EV-ECU, and measure at the equipment side.

(2)Resistance between C-108 EV-ECU connector terminal Nos.54 and 55
OK: 120 ± 20 Ω
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?

<Within 120 ± 20 Ω> Repair the wiring harness between the ETACS-ECU connector and the engine-ECU connector.

<Not within 120 ± 20 Ω> Replace the EV-ECU and register the ID codes (Refer to GROUP 54A, Immobilizer system - On-vehicles service ).