DTC C1555: Motor Relay Welding Failure [09/2014 - ]: Procedure

1. Check the connection of the power steering ECU assembly and power steering link assembly connectors.
2. Visually inspect the terminals of the power steering ECU assembly and power steering link assembly connectors.

   Result

   Result	Proceed to
   Normal	A
   Connectors not properly connected	B
   Power steering ECU assembly connector terminals abnormal	C
   Power steering link assembly connector terminals abnormal	D

Result: 

B 

CONNECT CONNECTORS PROPERLY 

Result: 

C 

REPLACE POWER STEERING ECU ASSEMBLY. Refer to  REMOVAL [09/2014 - ] 

Result: 

D 

REPLACE POWER STEERING LINK ASSEMBLY. Refer to  REMOVAL [09/2014 - 05/2018]  , or refer to  REMOVAL [05/2018 - 03/2019]  , or refer to  REMOVAL [03/2019 - ] 

Result: 

A 

See step  2

1. Disconnect the C4 power steering ECU assembly connector.
2. Disconnect the C1 power steering motor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C1-1 (W) - C4-2 (W)	Always	Below 1 Ω
   C1-2 (V) - C4-1 (V)	Always	Below 1 Ω
   C1-3 (U) - C4-3 (U)	Always	Below 1 Ω
   C1-1 (W) - Body ground	Always	10 kΩ or higher
   C1-2 (V) - Body ground	Always	10 kΩ or higher
   C1-3 (U) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Disconnect the C1 power steering motor connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1 (W) - 3 (U)	Always	0.07 to 10 Ω
   2 (V) - 1 (W)	Always	0.07 to 10 Ω
   3 (U) - 2 (V)	Always	0.07 to 10 Ω
   1 (W) - Power steering link housing*	Always	100 kΩ or higher
   2 (V) - Power steering link housing*	Always	100 kΩ or higher
   3 (U) - Power steering link housing*	Always	100 kΩ or higher

   1. *: Touch the negative probe to the power steering link assembly housing at the area shown in the illustration to perform the measurement.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	Power Steering Link Assembly
   *a	Area to Set Negative Probe
   *b	Component without harness connected (Power Steering Motor)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE POWER STEERING LINK ASSEMBLY. Refer to  REMOVAL [09/2014 - 05/2018]  , or refer to  REMOVAL [05/2018 - 03/2019]  , or refer to  REMOVAL [03/2019 - ] 

Result: 

OK 

See step  4

1. Remove the power steering link assembly.

   Refer to REMOVAL [09/2014 - 05/2018] , or refer to REMOVAL [05/2018 - 03/2019] , or refer to REMOVAL [03/2019 - ]

2. Clean off any dirt or foreign matter attached to the rack boots.
3. Using SST, move the rack ends and check that there are no cracks in the rack boots.

   OK

   There are no cracks.

   HINT: 

   Using SST, turn the pinion shaft to move the rack ends.

   • SST: 09616-00011 

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE POWER STEERING ECU ASSEMBLY. Refer to  REMOVAL [09/2014 - ] 

Result: 

NG 

REPLACE POWER STEERING LINK ASSEMBLY. Refer to  REMOVAL [09/2014 - 05/2018]  , or refer to  REMOVAL [05/2018 - 03/2019]  , or refer to  REMOVAL [03/2019 - ]