DTC C1427: Malfunction in Motor [10/2018 - ]: Procedure

1. Select the Active Test on the Techstream.

   Refer to DATA LIST / ACTIVE TEST [10/2018 - ]

   Chassis > ABS/VSC/TRAC > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Motor Relay	ABS motor relay	Relay ON/OFF	Operating sound of motor can be heard.

   Chassis > ABS/VSC/TRAC > Active Test 

   Tester Display
   Motor Relay

2. Check the operating sound of the ABS motor relay when operating it with the Techstream.

   Result

   Result	Proceed to
   The operating sound is heard.	A
   The operating sound is not heard.	B

Result: 

B 

See step  3

Result: 

A 

See step  2

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [10/2018 - ]

   Chassis > ABS/VSC/TRAC > Clear DTCs 

2. Turn the power switch off.
3. Turn the power switch on (READY).
4. Perform a road test.
5. Check if the same DTC is output.

   Refer to DTC CHECK / CLEAR [10/2018 - ]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   Result

   Result	Proceed to
   DTC C1427 is not output.	A
   DTC C1427 is output.	B

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2018 - ] 

Result: 

B 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022]  , or refer to  REMOVAL [07/2022 - ] 

1. Turn the power switch off.
2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

   OK

   The connector is securely connected.

3. Disconnect the A37 skid control ECU (brake booster with master cylinder assembly) connector.
4. Disconnect the A48 brake actuator assembly connector.
5. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

6. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A37-40 (+BM) - A48-10 (+BM)	Always	Below 1 Ω
   A37-40 (+BM) or A48-10 (+BM) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A48-1 (MGND) - Body ground	Always	Below 1 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Brake Actuator Assembly)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) 

Result: 

OK 

See step  5

1. Reconnect the A37 skid control ECU (brake booster with master cylinder assembly) connector.
2. Reconnect the A48 brake actuator assembly connector.
3. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [10/2018 - ]

   Chassis > ABS/VSC/TRAC > Clear DTCs 

4. Turn the power switch off.
5. Turn the power switch on (READY).
6. Perform a road test.
7. Check if the same DTC is output.

   Refer to DTC CHECK / CLEAR [10/2018 - ]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   Result

   Result	Proceed to
   DTC C1427 is not output.	A
   DTC C1427 is output.	B

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2018 - ] 

Result: 

B 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022]  , or refer to  REMOVAL [07/2022 - ]