1Nz-Fe Engine Control. Dtc P0351 Ignition Coil A Primary / Secondary Circuit

A Direct Ignition System (DIS) is used on this vehicle.
The DIS is a 1-cylinder ignition system in which each cylinder is ignited by one ignition coil and one spark plug is connected to the end of each secondary wiring. A powerful voltage, generated in the secondary wiring, is applied directly to each spark plug. The spark of the spark plugs passes from the center electrode to the ground electrodes.
The ECM determines the ignition timing and transmits the ignition (IGT) signals to each cylinder. Using the IGT signal, the ECM turns the power transistor inside the igniter on and off. The power transistor, in turn, switches on and off the current to the primary coil. When the current to the primary coil is cut off, a powerful voltage is generated in the secondary coil. This voltage is applied to the spark plugs, causing them to spark inside the cylinders. As the ECM cuts the current to the primary coil, the igniter sends back an ignition confirmation (IGF) signal to the ECM for each cylinder ignition.

Yaris. Ncp93, 131.1Nz-Fe Engine Control.Sfi System (For Sedan).
Dtc
P0351 Ignition Coil A Primary / Secondary Circuit

DTC No.	DTC Detection Condition	Trouble Area
P0351 P0352 P0353 P0354	No IGF signal to the ECM while the engine is running (1 trip detection logic).	Ignition system Open or short in IGF1 or IGT circuit (1 to 4) between ignition coil and ECM No. 1 ignition coil (No. 1 to No. 4 cylinder) ECM

Reference: Inspection using an oscilloscope.
While cranking or idling the engine, check the waveform between terminals IGT (1 to 4) and E1, and IGF1 and E1 of the ECM connector.
ECM Terminal Name
CH1: Between IGT (1 to 4) and E1
CH2: Between IGF1 and E1
Tester Range
5 V/DIV., 20 ms./DIV.
Condition
Idling

MONITOR DESCRIPTION

If the ECM does not receive any IGF signals despite transmitting the IGT signal, it interprets this as a fault in the igniter and stores a DTC.
If the malfunction is not repaired successfully, a DTC is stored 1 second after the engine is next started.

MONITOR STRATEGY

Related DTCs	P0351: Igniter (Cylinder 1) Malfunction P0352: Igniter (Cylinder 2) Malfunction P0353: Igniter (Cylinder 3) Malfunction P0354: Igniter (Cylinder 4) Malfunction
Required Sensors/Components (Main)	Igniter
Required Sensors/Components (Related)	Crankshaft position sensor
Frequency of Operation	Continuous
Duration	0.256 seconds for 2 times
MIL Operation	Immediate
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever following DTCs not present	None
Spark cut	Not operating
Either of following conditions met	A or B
A. Engine speed	1500 rpm or less
B. Starter	OFF
Either of following conditions met	C or D
C. Both of following conditions met	-
(a) Engine speed	500 rpm or less
(b) Battery voltage	6 V or higher
D. All of following conditions met	-
(a) Engine speed	More than 500 rpm
(b) Battery voltage	10 V or higher
(c) Number of sparks after CPU reset	5 sparks or more

TYPICAL MALFUNCTION THRESHOLDS

All of the following conditions are met	Condition A, B and C
A. Ignition signal fail counter	More than 2 times
B. Time after condition A is met	0.256 seconds or more
C. Ignition signal fail counter after condition B is met	More than 2 times

COMPONENT OPERATING RANGE

IGF signal

Igniter transmits IGF signal when it receives IGT signal from ECM

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the ignition switch to ON and turn the Techstream on.
Clear DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the Techstream on.
Start the engine.
Idle the engine for 10 seconds or more [A].
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [B].
Read pending DTCs.
HINT:
1. If a pending DTC is output, the system is malfunctioning.
2. If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0351, P0352, P0353 or P0354.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or N/A, perform steps [A] through [B] again.

If no pending DTC is output, perform a universal trip and check for permanent DTCs (YARIS_NCP93 RM000000PDK0T5X.html).
HINT:
1. If a permanent DTC is output, the system is malfunctioning.
2. If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

1.CHECK HARNESS AND CONNECTOR (NO. 1 IGNITION COIL - BODY GROUND)

Disconnect the No. 1 ignition coil connectors.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
C47-4 (GND) - Body ground	Always	Below 1 Ω
C48-4 (GND) - Body ground	Always	Below 1 Ω
C49-4 (GND) - Body ground	Always	Below 1 Ω
C50-4 (GND) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

2.INSPECT TERMINAL VOLTAGE (POWER SOURCE OF NO. 1 IGNITION COIL)

Disconnect the No. 1 ignition coil connectors.

Turn the ignition switch to ON.

Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
C47-1 (+B) - C47-4 (GND)	Ignition switch ON	11 to 14 V
C48-1 (+B) - C48-4 (GND)	Ignition switch ON	11 to 14 V
C49-1 (+B) - C49-4 (GND)	Ignition switch ON	11 to 14 V
C50-1 (+B) - C50-4 (GND)	Ignition switch ON	11 to 14 V

Text in Illustration
*a	Front view of wire harness connector (to No. 1 Ignition Coil)

Go to step 5

OK

3.CHECK HARNESS AND CONNECTOR (NO. 1 IGNITION COIL - ECM)

Disconnect the No. 1 ignition coil connectors.

Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
C47-2 (IGF) - C51-102 (IGF1)	Always	Below 1 Ω
C48-2 (IGF) - C51-102 (IGF1)	Always	Below 1 Ω
C49-2 (IGF) - C51-102 (IGF1)	Always	Below 1 Ω
C50-2 (IGF) - C51-102 (IGF1)	Always	Below 1 Ω
C47-3 (IGT1) - C51-57 (IGT1)	Always	Below 1 Ω
C48-3 (IGT2) - C51-56 (IGT2)	Always	Below 1 Ω
C49-3 (IGT3) - C51-55 (IGT3)	Always	Below 1 Ω
C50-3 (IGT4) - C51-54 (IGT4)	Always	Below 1 Ω
C47-2 (IGF) or C51-102 (IGF1) - Body ground	Always	10 kΩ or higher
C48-2 (IGF) or C51-102 (IGF1) - Body ground	Always	10 kΩ or higher
C49-2 (IGF) or C51-102 (IGF1) - Body ground	Always	10 kΩ or higher
C50-2 (IGF) or C51-102 (IGF1) - Body ground	Always	10 kΩ or higher
C47-3 (IGT1) or C51-57 (IGT1) - Body ground	Always	10 kΩ or higher
C48-3 (IGT2) or C51-56 (IGT2) - Body ground	Always	10 kΩ or higher
C49-3 (IGT3) or C51-55 (IGT3) - Body ground	Always	10 kΩ or higher
C50-3 (IGT4) or C51-54 (IGT4) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.CHECK WHETHER DTC OUTPUT RECURS (DTC P0351, P0352, P0353 OR P0354)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Clear the DTCs (YARIS_NCP93 RM000000PDK0T5X.html).

Shuffle the arrangement of the ignition coils (among No. 1 to No. 4 cylinders).
NOTICE:
Do not change the location of the connectors.

Perform a simulation test.

Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read DTCs.
Result
Result
Proceed to
Same DTC output
A
Different ignition coil DTC output
B
HINT:
Perform "Inspection After Repair" after replacing the No. 1 ignition coil (YARIS_NCP93 RM000004NJD006X.html).

Result
Result	Proceed to
Same DTC output	A
Different ignition coil DTC output	B

REPLACE NO. 1 IGNITION COIL (YARIS_NCP93 RM000002YO404IX.html)

REPLACE ECM (YARIS_NCP93 RM000001CN002IX.html)

5.CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - NO. 1 IGNITION COIL)

Disconnect the No. 1 ignition coil connectors.

Remove the No. 1 integration relay from the engine room relay block.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
C47-1 (+B) - 1E-2	Always	Below 1 Ω
C48-1 (+B) - 1E-2	Always	Below 1 Ω
C49-1 (+B) - 1E-2	Always	Below 1 Ω
C50-1 (+B) - 1E-2	Always	Below 1 Ω
C47-1 (+B) or 1E-2 - Body ground	Always	10 kΩ or higher
C48-1 (+B) or 1E-2 - Body ground	Always	10 kΩ or higher
C49-1 (+B) or 1E-2 - Body ground	Always	10 kΩ or higher
C50-1 (+B) or 1E-2 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK ECM POWER SOURCE CIRCUIT (YARIS_NCP93 RM000001F7102NX.html)

ECM Terminal Name	CH1: Between IGT (1 to 4) and E1 CH2: Between IGF1 and E1
Tester Range	5 V/DIV., 20 ms./DIV.
Condition	Idling