DTC B1504: Lost Communication with Steering SW: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Combination Meter / Data List.
5. Check the values by referring to the table below.
   COMBINATION METER
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Multi Display Select Switch	DISP switch in the steering pad switch assembly/OFF or ON	OFF: DISP switch in the steering pad switch assembly not pressed	-
   		ON: DISP switch in the steering pad switch assembly pressed	-
   Drive Monitor Reset SW	TRIP switch in the steering pad switch assembly/OFF or ON	OFF: TRIP switch in the steering pad switch assembly not pressed	-
   		ON: TRIP switch in the steering pad switch assembly pressed more than 1 second	-

   OK

   Steering pad switch assembly condition displayed on the Techstream changes with the actual switch operation.

NG → See step   2 

OK → See step   7 

1. Disconnect the L52 and z9 spiral cable with sensor sub-assembly connectors.
   Fig 1: Inspecting Spiral Cable With Sensor Sub-Assembly

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L52-3 (TX1) - z9-7	Always	Below 1 Ω
   L52-9 (IG) - z9-2	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Spiral Cable with Sensor Sub-assembly)

NG → See step   8 

OK: Go to next step 

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   L52-9 (IG) - Body ground	Power switch off	Below 1 V
   L52-9 (IG) - Body ground	Power switch on (IG)	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L27-29 (STRG) - L52-3 (TX1)	Always	Below 1 Ω
   L27-29 (STRG) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Replace the steering pad switch RH with a new or a known good one. Refer to REMOVAL .

   OK

   The operation of the combination meter assembly returns to normal.

NG → See step   6 

OK → END 

1. Replace the steering pad switch LH with a new or a known good one. Refer to REMOVAL .

   OK

   The operation of the combination meter assembly returns to normal.

NG → See step   7 

OK → END