Diagnosis Item 7: Diagnose when the M.U.T.-III cannot receive the data sent by ABS-ECU <vehicles with ABS> or ASTC-ECU <vehicles with ASTC>


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 CONDITIONS



PROBABLE CAUSES



  • Damaged harness wires and connectors
  • Power supply circuit malfunction of the ABS-ECU <vehicles with ABS> or ASTC-ECU <vehicles with ASTC>
  • Malfunction of the ABS-ECU <vehicles with ABS> or ASTC-ECU <vehicles with ASTC>

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-13 intermediate connector, C-119 joint connector (CAN1) and A-01 ABS-ECU <vehicles with ABS> or A-48 ASTC-ECU <vehicles with ASTC> connector



caution The 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.

Q. Is the check result normal?

Go to Step 2.

Repair the defective connector. Replace the joint connector as necessary.

STEP 2. Resistance measurement at C-119 joint connector (CAN1) and C-13 intermediate connector.
caution A digital multimeter should be used. For details refer to .
caution The test wiring harness should be used. For details refer to .


(1)Disconnect the joint connector (CAN1) and the intermediate connector, and measure at the wiring harness side.
(2)Turn the ignition switch to the LOCK (OFF) position.
(3)
caution When measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.

(4)Continuity between C-119 joint connector (CAN1) terminal No.5 and C-13 intermediate connector terminal No.14 <LHD>
OK: Continuity (2 Ω or less)

(5)Continuity between C-119 joint connector (CAN1) terminal No.5 and C-13 intermediate connector terminal No.13 <RHD>
OK: Continuity (2 Ω or less)

(6)Continuity between C-119 joint connector (CAN1) terminal No.16 and C-13 intermediate connector terminal No.15 <LHD>
OK: Continuity (2 Ω or less)

(7)Continuity between C-119 joint connector (CAN1) terminal No.16 and C-13 intermediate connector terminal No.12 <RHD>
OK: Continuity (2 Ω or less)
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?

<All the resistances measure 2 Ω or less> Go to Step 3 .

NO : <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between joint connector (CAN1) and intermediate connector (C-13).

STEP 3. Resistance measurement at C-13 intermediate connector and A-01 ABS-ECU <vehicles with ABS> or A-48 ASTC-ECU <vehicles with ASTC> connector.
caution A digital multimeter should be used. For details refer to .
caution The test wiring harness should be used. For details refer to .



(1)Disconnect the intermediate connector and the ABS-ECU <vehicles with ABS> or ASTC-ECU <vehicles with ASTC> connector, and measure at the wiring harness side.
(2)Turn the ignition switch to the LOCK (OFF) position.
(3)
caution When measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.

(4)Continuity between C-13 intermediate connector terminal No.15 and A-01 ABS-ECU connector terminal No.23 <LHD-vehicles with ABS>
OK: Continuity (2 Ω or less)

(5)Continuity between C-13 intermediate connector terminal No.12 and A-01 ABS-ECU connector terminal No.23 <RHD-vehicles with ABS>
OK: Continuity (2 Ω or less)

(6)Continuity between C-13 intermediate connector terminal No.15 and A-48 ASTC-ECU connector terminal No.23 <LHD-vehicles with ASTC>
OK: Continuity (2 Ω or less)

(7)Continuity between C-13 intermediate connector terminal No.12 and A-48 ASTC-ECU connector terminal No.23 <RHD-vehicles with ASTC>
OK: Continuity (2 Ω or less)

(8)Continuity between C-13 intermediate connector terminal No.14 and A-01 ABS-ECU connector terminal No.34 <LHD-vehicles with ABS>
OK: Continuity (2 Ω or less)

(9)Continuity between C-13 intermediate connector terminal No.13 and A-01 ABS-ECU connector terminal No.34 <RHD-vehicles with ABS>
OK: Continuity (2 Ω or less)

(10)Continuity between C-13 intermediate connector terminal No.14 and A-48 ASTC-ECU connector terminal No.34 <LHD-vehicles with ASTC>
OK: Continuity (2 Ω or less)

(11)Continuity between C-13 intermediate connector terminal No.13 and A-48 ASTC-ECU connector terminal No.34 <RHD-vehicles with ASTC>
OK: Continuity (2 Ω or less)
caution Strictly observe the specified wiring harness repair procedure. For details refer to .

Q. Is the check result normal?

<All the resistances measure 2 Ω or less> Power supply to the ABS-ECU <vehicles with ABS> or ASTC-ECU <vehicles with ASTC> may be suspected. Diagnose the ABS or ASTC. Refer to <vehicles with ABS> or <vehicles with ASTC>.

NO : <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between intermediate connector (C-13) and the ABS-ECU <vehicles with ABS> or ASTC-ECU <vehicles with ASTC> connector.