DTC C1311/11: Open in Main Relay 1 Circuit; DTC C1312/12: Short in Main Relay 1 Circuit; DTC C1313/13: Open in Main Relay 2 Circuit; DTC C1314/14: Short in Main Relay 2 Circuit: Procedure

1. Remove the ABS MAIN1, ABS MAIN2 and ABS MAIN3 fuses from the engine room No. 2 junction block/relay block.
2. Measure the resistance of the fuses.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   ABS MAIN1 fuse	Always	Below 1 Ω
   ABS MAIN2 fuse	Always	Below 1 Ω
   ABS MAIN3 fuse	Always	Below 1 Ω

NG → REPLACE FUSE 

OK: Go to next step 

1. Disconnect the A19 and A21 ECU connectors.
   Fig 1: Identifying A19 And A21 Skid Control ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   A19-43 (+BI1) - Body ground	Always	11 to 14 V
   A21-38 (+BI2) - Body ground	Always	11 to 14 V
   A19-29 (+BI3) - Body ground	Always	11 to 14 V
   A21-22 (+BI4) - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Clear the DTC. Refer to DTC CHECK / CLEAR .
2. Turn the power switch ON (IG).
3. Check if the same DTCs are recorded. Refer to DTC CHECK / CLEAR .

   HINT: 

   Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

   RESULT
   
   

   Condition	Proceed to
   DTCs (C1311/11, C1312/12, C1313/13 and C1314/14) are not output	A
   DTCs (C1311/11, C1312/12, C1313/13 and C1314/14) are output	B

B → See step   5 

A → See step   4