DTC C1437: Lost Communication with ECM [08/2015 - 08/2019]: Procedure

1. Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to the DTC (Refer to CHECK FOR INTERMITTENT PROBLEMS [08/2015 - 08/2019] ).
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   EFI Communication Open	ECM communication open circuit detection/ Error or Normal	Normal	-

   OK

   Normal (there are no momentary interruptions).

   HINT: 

   Perform the above inspection before removing the sensor and disconnecting the connector.

Result: 

NG 

See step  3

Result: 

OK 

See step  2

1. Turn the ignition switch off.
2. Clear the DTC (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
3. Start the engine.
4. Drive the vehicle at a speed of 15 km/h (9 mph) or more for 10 seconds or more.
5. Check that no CAN communication system DTC is output (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
6. Check if the same DTC is output (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
   RESULT
   
   

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

Result: 

A 

USE SIMULATION METHOD TO CHECK 

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

Result: 

B 

REPLACE BRAKE ACTUATOR ASSEMBLY 

(Refer to REMOVAL [08/2015 - 08/2019] )

Result: 

C 

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

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

1. Turn the ignition switch off.
2. Repair or replace the harness or connector.
3. Check for any momentary interruption between the skid control ECU and ECM (Refer to CHECK FOR INTERMITTENT PROBLEMS [08/2015 - 08/2019] ).
4. Check that there is no momentary interruption.

Result: 

NEXT 

See step  4

1. Turn the ignition switch off.
2. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
3. Start the engine.
4. Drive the vehicle at a speed of 15 km/h (9 mph) or more for 10 seconds or more.
5. Check that no CAN communication system DTC is output (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
6. Check if the same DTC is output (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
   RESULT
   
   

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

Result: 

A 

END 

Result: 

B 

REPLACE BRAKE ACTUATOR ASSEMBLY 

(Refer to REMOVAL [08/2015 - 08/2019] )

Result: 

C 

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

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