DTC C1437: Lost Communication with ECM [12/2017 - 09/2018]: Procedure

1. Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC.

   Refer to CHECK FOR INTERMITTENT PROBLEMS [12/2017 - 09/2018]

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   EFI Communication Open	ECM communication open detection	Error or Normal	Error: Momentary interruption detected Normal: Momentary interruption not detected	After a momentary interruption occurs, if there is no momentary interruption for 1 second, it switches from "Error" to "Normal".
   EFI Communication Invalid	ECM communication invalid detection	Error or Normal	Error: ECM communication invalid state detected Normal: ECM communication invalid state not detected	After ECM communication invalid state occurs, if there no further invalid state occurs, it switches from "Error" to "Normal".

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display
   EFI Communication Open
   EFI Communication Invalid

   OK

   Normal (There are no momentary interruptions.)

   HINT: 

   Perform the above inspection before removing the connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CHECK CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2017 - 09/2018] 

Result: 

OK 

See step  2

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [12/2017 - 09/2018]

   Chassis > ABS/VSC/TRAC > Clear DTCs 

2. Turn the engine switch off.
3. Start the engine.
4. Perform a road test.
5. Check that no CAN communication system DTCs are output.

   Refer to DIAGNOSIS SYSTEM [12/2017 - 09/2018]

6. Check if the same DTC is output.

   Refer to DTC CHECK / CLEAR [12/2017 - 09/2018]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   Result

   Result	Proceed to
   DTC C1437 is not output.	A
   DTC C1437 is output.	B
   CAN communication system DTCs are output.	C

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2017 - 09/2018] 

Result: 

B 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [12/2017 - 09/2018] 

Result: 

C 

INSPECT CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2017 - 09/2018]