DTC C1783: Speed Signal Communication Error [08/2015 - 08/2019]: Procedure

1. Clear the DTC (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
2. Perform a road test.
3. Check if DTC C1783 and U0122 are output (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
   RESULT
   
   

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

Result: 

B 

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - 08/2017] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2017 - 08/2019] )

Result: 

A 

See step  2

1. Check if DTC C1783 and a brake control system speed sensor malfunction DTC (C0200/31, C0205/32, C0210/33 or C0215/35) are output (Refer to DTC CHECK / CLEAR [08/2015 - 08/2017] , or refer to DTC CHECK / CLEAR [08/2017 - 08/2019] ).
   RESULT
   
   

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

Result: 

B 

GO TO BRAKE CONTROL SYSTEM (DIAGNOSTIC TROUBLE CODE CHART) 

(Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2015 - 08/2017] , or refer to DIAGNOSTIC TROUBLE CODE CHART [08/2017 - 08/2018] , or refer to DIAGNOSTIC TROUBLE CODE CHART [08/2018 - 08/2019] )

Result: 

A 

See step  3

1. Turn the ignition switch off.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON, and turn the Techstream main switch on.
4. Enter the following menus: Chassis / Air suspension / Data List.
   AIR SUSPENSION
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   FR Wheel Speed	Wheel speed (Front right) reading / min.: 0 km/h (0 mph), max.: 255 km/h (159 mph)	Actual vehicle speed	Speed indicated on the speedometer
   FL Wheel Speed	Wheel speed (Front left) reading / min.: 0 km/h (0 mph), max.: 255 km/h (159 mph)	Actual vehicle speed	Speed indicated on the speedometer
   RR Wheel Speed	Wheel speed (Rear right) reading / min.: 0 km/h (0 mph), max.: 255 km/h (159 mph)	Actual vehicle speed	Speed indicated on the speedometer
   RL Wheel Speed	Wheel speed (Rear left) reading / min.: 0 km/h (0 mph), max.: 255 km/h (159 mph)	Actual vehicle speed	Speed indicated on the speedometer

   OK

   Vehicle speed indicated on the Techstream indicates the actual speed.

Result: 

OK 

REPLACE SUSPENSION CONTROL ECU 

(Refer to REMOVAL [08/2015 - ] )

Result: 

NG 

GO TO BRAKE CONTROL SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - 08/2017] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2017 - ] )