C0274 SHORT CIRCUIT OF MOTOR RELAY

1. Set the starter switch to "LOCK", remove the ABS motor relay from the relay block.
2. Measure the resistance between 3rd and 5th terminals.
   Standard: ∞Ω
   
   
   　

Abnormality of the ABS motor relay.

[1]-3

3. Measure the resistance between 1st and 2nd terminals of the ABS motor relay.
   Standard: 125-187.5 Ω
   
   
   　

Abnormality of the ABS motor relay.

[1]-4

4. Check the continuity between 3rd and 5th terminals of the 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.

[2] ECU CHECK

1. Install the ABS motor 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 ECU power supply circuit.

[2]-3

3. Measure the voltage between 12th 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. Confirm the DTC C0274 is inactive

   • Start the engine and let it idling condition.
   • Verify the DTC C0274 is inactive.

   

2. DTC Clear

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

   

C0274 is reoccur: Return to first process Other DTC appear: Refer to concerned Trouble shooting

Complete