DTC C1201/51 Engine Control System Malfunction: Description

If a malfunction in the engine control system is detected, the operations of VSC and TRAC are prohibited by the fail-safe function. When the signals from the engine are input normally, the fail-safe is cancelled and the DTC is not stored.

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION) 
   1. Using the intelligent tester, check for any momentary interruption in the wire harness and connector corresponding to a DTC (See CHECK FOR INTERMITTENT PROBLEMS  ).

      ABS / VSC: 

      ITEM (DISPLAY) MEASUREMENT ITEM / RANGE (DISPLAY) AND NORMAL CONDITION CHART
      
      

      Item (Display)	Measurement Item / Range (Display)	Normal Condition
      EFI COM OPN	EFI communication open detection / ERROR or NORMAL	ERROR: Momentary interruption NORMAL: Normal

      OK: 

      There are no momentary interruptions. 

      HINT:

      Perform the above inspection before removing the sensor and connector.

   NG : Go to step   3 

   OK : Go to Next Step 

2. CHECK DTC FOR ENGINE CONTROL SYSTEM 
   1. Clear the DTC (See DTC CHECK / CLEAR ).
   2. Check for the DTC (See DTC CHECK / CLEAR ).

      Result 

      DISPLAY (DTC OUTPUT) AND PROCEED TO REFERENCE CHART
      
      

      Display (DTC Output)	Proceed To
      DTC (engine control system) is not output	A
      DTC (engine control system) is output	B (See FREEZE FRAME DATA )

   B : REPAIR ENGINE CONTROL SYSTEM ACCORDING TO DTC OUTPUT 

   A : REPLACE ECM 

3. REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM TO SKID CONTROL ECU) 

   NEXT 

4. RECONFIRM DTC 
   1. Clear the DTC (See DIAGNOSIS SYSTEM  ).
   2. Perform a road test.
   3. Check if the same DTC is recorded (See DIAGNOSIS SYSTEM  ).

      Result 

      DISPLAY (DTC OUTPUT) AND PROCEED TO REFERENCE CHART
      
      

      Display (DTC Output)	Proceed To
      DTC (C1201/51) is not output	A
      DTC (C1201/51) is output	B

   B : Go to step   2 

   A : END