C0273  DISCONNECTION OF MOTOR RELAY

1. Set the starter switch to "LOCK", check the ABS 50A fusible link.
   Standard: No abnormality

Replace the fusible link.

[2]RELAY CHECK

1. Disconnect the 31 pin connector of ECU.
2. Measure the resistance between 1st and 12th terminals of the 31 pin connector.
   Standard: 100-210 Ω
   
   

Go to the item "6".

[2]-3

3. Remove the ABS motor relay, measure the resistance between 3rd and 5th terminals.
   Standard: ∞Ω
   
   
   　

Abnormality of the ABS motor relay.

[3] WIRE HARNESS CHECK

1. Disconnect the 24 pin connector of ABS actuator.
2. Measure the resistance between 2nd terminal of the 24 pin connector of ABS actuator (chassis harness side) and 1st terminal of the ABS motor relay (socket side).
   Standard: Less than 5 Ω
   
   
   　

Abnormality of the wire harness.

[4] RELAY CHECK

1. Check the continuity between 3rd and 5th terminals of ABS motor relay when a battery voltage was applied between 1st and 2nd terminals.
   Standard:
   Turning on electricity between 1st and 2nd terminals: It is conducted between 3rd and 5th terminals.
   Not turning on electricity: It is not conducted between 3rd and 5th terminals.
   
   
   　

Abnormality of the ABS motor relay.

[5] ECU CHECK

1. Connect the connector and relay, turn the starter switch to "ON".
2. Measure the voltage between 1st and 2nd terminals of the 31 pin connector of ECU. (Leaving the connector connected with ECU.)
   Standard: 20-28V
   
   

Abnormality of the ECU power supply circuit.

[5]-3

3. Measure the voltage between 12th and 2nd terminals of the 31 pin connector. (Leaving the connector connected with ECU.)
   Standard: 20-28V
   
   

Abnormality of the ECU power supply circuit.

[5]-4

4. Measure the voltage between 18th and 2nd terminals of the 31 pin connector. (Leaving the connector connected with ECU.)
   Standard: Less than 2V
   
   
   　

Abnormality of the ECU power supply circuit.

Normal.

1. Measure the resistance between 1st terminal of the 31 pin connector of ECU (chassis harness side) and 2nd terminal of the ABS motor relay (socket side).
   Standard: Less than 5 Ω
   
   

Abnormality of the wire harness.

[6]-2

2. Measure the resistance between 12th terminal of the 31 pin connector of ECU (chassis harness side) and 3rd terminal of the ABS motor relay (socket side).
   Standard: Less than 5 Ω
   
   

Abnormality of the wire harness.

[7] RELAY CHECK

1. Remove the ABS solenoid relay, measure the resistance between 1st and 2nd terminals.
   Standard: 128-187.5 Ω
   
   

Abnormality of the ABS solenoid relay.

Normal.

1. Disconnect 24 pin connector of ABS actuator.
2. Measure the resistance between 18th terminal of the 31 pin connector of ECU (chassis harness side) and 3rd terminal of the 24 pin connector of ABS actuator (chassis harness side)
   Standard: More than 5 Ω

   
   　

Abnormality of the wire harness.

Normal.

1. Confirm the DTC C0273 is inactive

   • Start the engine and let it idling condition.
   • Verify the DTC C0273is inactive.

   

2. DTC Clear

   • Clear the DTC with Hino DX
   • Confirm the same DTC is not reoccurred

   

C0273 is reoccur: Return to first process Other DTC appear: Refer to concerned Trouble shooting

Complete