Inspection Procedure

HINT:

• Check the condition of each related circuit connector before troubleshooting (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
• When C1774 is output, inspect and repair the trouble areas indicated by C1774 first (see DTC C1774 LOW BATTERY POSITIVE VOLTAGE  ).

1. CHECK FOR DTC 
   1. Check if any speed sensor DTCs (Brake control system trouble code: C0200/31, C0205/32, C0210/33, C0215/34, C1235/35, C1236/36, C1238/38, C1239/39) or a CAN communication DTC (U0122) is output together with DTC C1776.

      Result 

      RESULT REFERENCE
      
      

      Result	Proceed to
      Only DTC C1776 is output	A
      Speed sensor DTC is output (Brake control system trouble code)	B
      CAN communication DTC is output	C

   B: REPAIR CIRCUITS INDICATED BY OUTPUT DTCS  (See DIAGNOSTIC TROUBLE CODE CHART )

   C: REPAIR CIRCUITS INDICATED BY OUTPUT DTCS  (See DIAGNOSTIC TROUBLE CODE CHART )

   A: GO TO Next Step 

2. READ VALUE OF INTELLIGENT TESTER (VEHICLE SPEED) 
   1. Connect the intelligent tester (with CAN VIM) to the DLC3.
   2. Turn the power switch ON (READY) and turn the intelligent tester main switch on.
   3. Select "DATA LIST" mode on the intelligent tester (see DATA LIST / ACTIVE TEST  ).

      Absorber control ECU 

      DATA LIST - ABSORBER CONTROL ECU
      
      

      Item	Measurement Item/ Range (Display)	Normal Condition	Diagnostic Note
      VEHICLE SPD	Vehicle speed reading / min.: 0 km/h (0 mph), max: 255 km/h (158 mph)	Actual wheel speed	Speed indicated on speedometer

   4. Check that there is no difference between the speed value output from the skid control ECU displayed on the intelligent tester and the speed value displayed on the speedometer when driving the vehicle.

      OK: The speed value output from the skid control ECU displayed on the intelligent tester is the same as the actual vehicle speed. 

   NG: CHECK BRAKE CONTROL SYSTEM (SPEED SENSOR SIGNAL) (See  HOW TO PROCEED WITH TROUBLESHOOTING   ) 

   OK: GO TO Next Step 

3. RECONFIRM DTC 
   1. Clear the DTC (see FAIL-SAFE CHART  ).
   2. Perform a road test.
   3. Check if the same DTC is recorded (see FAIL-SAFE CHART  ).

      Result 

      RESULT REFERENCE
      
      

      Result	Proceed to
      DTC is output	A
      DTC is not output (When troubleshooting in accordance with the PROBLEM SYMPTOMS TABLE )	B
      DTC is not output	C

   B: PROCEED TO NEXT INSPECTION PROCEDURE SHOWN IN  PROBLEM SYMPTOMS TABLE  

   C: END 

   A: REPLACE ABSORBER CONTROL ECU