Dtc 12 Crankshaft Position Sensor Circuit Malfunction


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT CRANKSHAFT POSITION SENSOR

CHECK ECM (TDC, NE SIGNAL)

CHECK HARNESS AND CONNECTOR (ECM - CRANKSHAFT POSITION SENSOR)

DTC 12 Crankshaft Position Sensor Circuit Malfunction


DESCRIPTION

The crankshaft position sensor in the Engine Control System contains a signal plate and a pickup coil for TDC signal. The TDC signal plate has 1 tooth on its outer circumference. The TDC signal sensor generates 1 signal for every engine revolution. The ECM detects the top dead center position based on the TDC signals.

DTC No.
DTC Detection Condition
Trouble Area
12
No TDC signal to ECM at 400 rpm or more
  1. Open or short in crankshaft position sensor circuit
  2. Crankshaft position sensor
  3. ECM

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 12 Crankshaft Position Sensor Circuit Malfunction


INSPECTION PROCEDURE

1.INSPECT CRANKSHAFT POSITION SENSOR


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 12 Crankshaft Position Sensor Circuit Malfunction

  1. Check the crankshaft position sensor installation.

  1. Disconnect the C5 crankshaft position sensor connector.

  1. Measure the resistance of the crankshaft position sensor.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1 - 2
    		Cold
    		19 to 32 Ω
    1 - 2
    		Hot
    		24 to 37 Ω
    NOTICE:
    In the chart above, the terms "Cold" and "Hot" refer to the temperature of the sensor. "Cold" means approximately -10 to 50°C (14 to 122°F). "Hot" means approximately 50 to 100°C (122 to 212°F).


NG
REPLACE CRANKSHAFT POSITION SENSOR
OK


2.CHECK ECM (TDC, NE SIGNAL)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 12 Crankshaft Position Sensor Circuit Malfunction

  1. While cranking or idling, measure the waveform according to the value(s) in the table below.

    OK:
    Tester Connection
    		Specified Condition
    E20-17 (TDC+) - E20-16 (TDC-)
    		Correct waveform is as shown
    E20-19 (NE+) - E20-18 (NE-)
    		Correct waveform is as shown
    Tool Setting
    		Condition
    2 V/DIV., 20 msec./DIV.
    		During idling


OK
REPLACE ECM
NG


3.CHECK HARNESS AND CONNECTOR (ECM - CRANKSHAFT POSITION SENSOR)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 12 Crankshaft Position Sensor Circuit Malfunction

  1. Disconnect the C5 crankshaft position sensor connector.

  1. Disconnect the E20 ECM connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    C5-1 (+) - E20-17 (TDC+)
    		Below 1 Ω
    C5-2 (-) - E20-16 (TDC-)
    		Below 1 Ω
    E20-17 (TDC+) - E20-16 (TDC-)
    		10 kΩ or higher
    C5-1 (+) or E20-17 (TDC+) - Body ground
    		10 kΩ or higher
    C5-2 (-) or E20-16 (TDC-) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CHECK FOR INTERMITTENT PROBLEMS