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Diagnostic Item 32: Diagnose when the scan tool (M.U.T.-IIISE) cannot receive the data sent by telematics control unit (TCU). <Vehicles with telematics control unit (TCU)>
 
 
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 "the scan tool (M.U.T.-IIISE) cannot receive the sent data from the telematics control unit (TCU)" when the scan tool (M.U.T.-IIISE) checks the periodically sent data from each ECU and cannot receive the telematics control unit (TCU) data only.
 
 
TROUBLE JUDGMENT CONDITIONS
Scan tool (M.U.T.-IIISE) judges the trouble when the periodically sent data from telematics control unit (TCU) cannot be received.
 
 
TROUBLESHOOTING HINTS
  • Damaged harness wires and connectors
  • Power supply circuit malfunction of the telematics control unit (TCU)
  • Malfunction of the telematics control unit (TCU)
  • Malfunction of the gateway-ECU
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Connector check: gateway-ECU connector, telematics control unit (TCU) connector and joint connector (CAN5).
cautionThe strand end of the twist wire should be within 10 cm (3.9 inches) from the connector. For details refer to .
Is the check result normal?
Go to Step 2.
Repair the defective connector. Replace the connector as necessary.
 
STEP 2. Resistance measurement at gateway-ECU connector and joint connector (CAN5).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect the gateway-ECU connector and the joint connector (CAN5), 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 gateway-ECU connector terminal No. 6 and joint connector (CAN5) terminal No. 1
OK: The resistance should be 2 ohms or less
(5) Continuity between gateway-ECU connector terminal No. 5 and joint connector (CAN5) terminal No. 12
OK: The resistance should be 2 ohms or less
Is the check result normal?
<All the resistances measure 2 ohms or less> Go to Step 3 .
<Either or all of the resistances measure more than 2 ohms> Repair the wiring harness between gateway-ECU connector and the joint connector (CAN5).
 
STEP 3. Resistance measurement at gateway-ECU connector.
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Remove the gateway-ECU, and measure at the equipment side.
(2) Resistance at gateway-ECU connector terminal Nos. 5 and 6
OK: 1 kΩ or more
Is the check result normal?
<1 kΩ or more> Go to Step 4.
<Less than 1 kΩ> Check the gateway-ECU connector, and repair if necessary. If the gateway-ECU connector is in good condition, replace the gateway-ECU.
 
STEP 4. Resistance measurement at gateway-ECU connector and telematics control unit (TCU) connector.
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect the gateway-ECU connector and the telematics control unit (TCU) connector, 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 gateway-ECU connector terminal No. 8 and telematics control unit (TCU) connector terminal No. 33
OK: The resistance should be 2 ohms or less
(5) Continuity between gateway-ECU connector terminal No. 7 and telematics control unit (TCU) connector terminal No. 13
OK: The resistance should be 2 ohms or less
Is the check result normal?
<All the resistances measure 2 ohms or less> Go to Step 5 .
<Either or all of the resistances measure more than 2 ohms> Repair the wiring harness between gateway-ECU connector and the telematics control unit (TCU) connector.
 
STEP 5. Resistance measurement at gateway-ECU connector (short to ground check)
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect the gateway-ECU connector and telematics control unit (TCU) connector 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) Measure the resistance between gateway-ECU connector terminal No. 8 and body ground. <CAN_H>
OK: 1 kΩ or more
(5) Measure the resistance between gateway-ECU connector terminal No. 7 and body ground. <CAN_L>
OK: 1 kΩ or more
Is the check result normal?
<1 kΩ or more> Go to Step 6 .
<Less than 1 kΩ> Repair the wiring harness between the gateway-ECU connector and telematics control unit (TCU) connector.
 
STEP 6. Voltage measurement at gateway-ECU connector (short to power supply check)
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
cautionStrictly observe the specified wiring harness repair procedure. For details refer to
(1) Disconnect the gateway-ECU connector and telematics control unit (TCU) connector and measure at the wiring harness side.
(2) Connect the negative battery terminal, and turn the ignition switch to the "ON" position.
(3) Measure the voltage between gateway-ECU connector terminal No. 8 and body ground. <CAN_H>
OK: 1.0 volt or less
(4) Measure the voltage between gateway-ECU connector terminal No. 7 and body ground. <CAN_L>
OK: 1.0 volt or less
Is the check result normal?
<1.0 volt or less> Go to Step 7.
<More than 1.0 volt> Repair the wiring harness between the gateway-ECU connector and telematics control unit (TCU) connector.
 
STEP 7. Resistance measurement at gateway-ECU connector (line-to-line short check)
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect the gateway-ECU connector and telematics control unit (TCU) connector 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) Measure the resistance between gateway-ECU connector terminal Nos. 8 and 7.
OK: 1 kΩ or more
Is the check result normal?
<1 kΩ or more> Go to Step 8.
<Less than 1 kΩ> Repair the wiring harness between the gateway-ECU connector and telematics control unit (TCU) connector.
 
STEP 8. Resistance measurement at gateway-ECU connector.
cautionA digital multimeter should be used. For details refer to .
(1) Remove the gateway-ECU, and measure at the equipment side.
(2) Resistance at gateway-ECU connector terminal Nos. 8 and 7
OK: 120 ± 20 ohms
Is the check result normal?
<Within 120 ± 20 ohms> Go to Step 9.
<Not within 120 ± 20 ohms> Replace the gateway-ECU.
 
STEP 9. Resistance measurement at telematics control unit (TCU) connector.
cautionA digital multimeter should be used. For details refer to .
(1) Remove the telematics control unit (TCU), and measure at the equipment side.
(2) Resistance at telematics control unit (TCU) connector terminal Nos. 33 and 13
OK: 120 ± 20 ohms
Is the check result normal?
<Within 120 ± 20 ohms> The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
<Not within 120 ± 20 ohms> Replace the telematics control unit (TCU).