DTC C1522: Motor Circuit Malfunction; DTC C1523: Motor Circuit Malfunction; DTC C1524: Motor Circuit Malfunction; DTC C1555: Motor Relay Welding Failure: Procedure

1. Check the connection condition of the z1 power steering motor connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

   Power steering motor connector is securely connected and locked to the power steering ECU assembly.

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Power Steering ECU Assembly)

NG → CONNECT CONNECTOR SECURELY 

OK: Go to next step 

1. Turn the ignition switch off.
2. Connect the Techstream to the DLC3.
3. Start the engine.
4. Turn the Techstream on.
5. Enter the following menus: Chassis / EMPS / Data List.
6. Select the items "Motor Terminal Volt(U)", "Motor Terminal Volt(V)" and "Motor Terminal Volt(W)" in the Data List and read the value displayed on the Techstream.
   EMPS
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Motor Terminal Volt(U)	Motor terminal voltage (U phase)/ Min.: 0.000 V Max.: 98.000 V	Value changes between 4 and 35 V	The engine is running and the steering wheel is being turned.
   Motor Terminal Volt(V)	Motor terminal voltage (V phase)/ Min.: 0.000 V Max.: 98.000 V	Value changes between 4 and 35 V	The engine is running and the steering wheel is being turned.
   Motor Terminal Volt(W)	Motor terminal voltage (W phase)/ Min.: 0.000 V Max.: 98.000 V	Value changes between 4 and 35 V	The engine is running and the steering wheel is being turned.

   RESULT
   
   

   Result	Proceed to
   During steering operation, value changes between 4 and 35 V.	A
   During steering operation, voltage is not generated or voltage outside specified range is generated.	B

B → See step   3 

A → See step   4