DTC C1201/51: Engine Control System Malfunction (TO 12/2010): Procedure

WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC. Refer to CHECK FOR INTERMITTENT PROBLEMS .

ABS/VSC/TRAC

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
EFI Open	EFI communication open detection / OPN DET or NORMAL	OPN DET: Momentary interruption NORMAL: Normal	-

There are no momentary interruptions.

HINT:

Perform the above inspection before removing the sensor and connector.

NG → See step 3

OK: Go to next step

CHECK DTC FOR ENGINE CONTROL SYSTEM

Clear the DTC (engine control system).

Check the DTC (engine control system).

Result

Result	Proceed to
DTC (engine control system) is not output	A
DTC (engine control system) is output	B

B → REPAIR ENGINE CONTROL SYSTEM ACCORDING TO DTC OUTPUT

A → REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM TO SKID CONTROL ECU)
NEXT: Go to next step

RECONFIRM DTC

Clear the DTC. Refer to DTC CHECK / CLEAR .
Perform a road test.

Check that the same DTC is recorded. Refer to DTC CHECK / CLEAR .

Result

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

B → See step 2

A → END