DTC P0351 Ignition Coil "A" Primary Control Circuit/Open: Notes

WARNING: This page is about a different variant/trim than selected.

DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Improper idling
Poor driving performance

CAUTION: After servicing or replacing faulty parts, perform Clear Memory Mode <Ref. to OPERATION , Clear Memory Mode.>, and Inspection Mode <Ref. to PROCEDURE , Inspection Mode.>.

Wiring diagram:

Engine Electrical System <Ref. to WIRING DIAGRAM , Engine Electrical System.>

Fig 1: Ignition Coil "A" Primary Control Circuit/Open - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK IGNITION COIL POWER SUPPLY CIRCUIT. Turn the ignition switch to OFF. Disconnect the connector from ignition coil. Turn the ignition switch to ON. Measure the voltage between ignition coil connector and engine ground. Connector & terminal DTC P0351; (E31) No. 3 (+) - Engine ground (-): DTC P0352; (E32) No. 3 (+) - Engine ground (-): DTC P0353; (E33) No. 3 (+) - Engine ground (-): DTC P0354; (E34) No. 3 (+) - Engine ground (-): DTC P0355; (E45) No. 3 (+) - Engine ground (-): DTC P0356; (E46) No. 3 (+) - Engine ground (-):	Is the voltage 10 V or more?	Go to step 2.	Repair the harness and connector. NOTE: In this case, repair the following item: Open or short to ground in harness of power supply circuit Blown out of fuse (M/B No. 23) Poor contact of IG relay connector Poor contact of coupling connector Faulty IG relay
2 CHECK HARNESS OF IGNITION COIL GROUND CIRCUIT. Turn the ignition switch to OFF. Measure the resistance of harness between ignition coil connector and engine ground. Connector & terminal DTC P0351; (E31) No. 2 - Engine ground: DTC P0352; (E32) No. 2 - Engine ground: DTC P0353; (E33) No. 2 - Engine ground: DTC P0354; (E34) No. 2 - Engine ground: DTC P0355; (E45) No. 2 - Engine ground: DTC P0356; (E46) No. 2 - Engine ground:	Is the resistance less than 5 Ω?	Go to step 3.	Repair the open circuit in harness between ignition coil connector and engine grounding terminal.
3 CHECK HARNESS BETWEEN ECM AND IGNITION COIL CONNECTOR. Disconnect the connector from ECM. Measure the resistance between ignition coil connector and engine ground. Connector & terminal DTC P0351; (E31) No. 1 - Engine ground: DTC P0352; (E32) No. 1 - Engine ground: DTC P0353; (E33) No. 1 - Engine ground: DTC P0354; (E34) No. 1 - Engine ground: DTC P0355; (E45) No. 1 - Engine ground: DTC P0356; (E46) No. 1 - Engine ground:	Is the resistance 1 MΩ or more?	Go to step 4.	Repair the ground short circuit of harness between ECM connector and ignition coil connector.
4 CHECK HARNESS BETWEEN ECM AND IGNITION COIL CONNECTOR. Measure the resistance of harness between ECM connector and ignition coil connector. Connector & terminal DTC P0351; (E158) No. 37 - (E31) No. 1: DTC P0352; (E158) No. 35 - (E32) No. 1: DTC P0353; (E158) No. 38 - (E33) No. 1: DTC P0354; (E158) No. 36 - (E34) No. 1: DTC P0355; (E158) No. 26 - (E45) No. 1: DTC P0356; (E158) No. 39 - (E46) No. 1:	Is the resistance less than 1 Ω?	Go to step 5.	Repair the open circuit in harness between ECM connector and ignition coil connector.
5 CHECK FOR POOR CONTACT. Check for poor contact of ECM connector.	Is there poor contact of ECM connector?	Repair the poor contact of ECM connector.	Go to step 6.
6 CHECK SPARK PLUG CONDITION. Remove the spark plug of the corresponding cylinder. <Ref. to REMOVAL , Spark Plug.> Check the spark plug condition. <Ref. to INSPECTION , Spark Plug.>	Is the check result OK?	Replace the ignition coil. <Ref. to IGNITION COIL .>	Replace the spark plug. <Ref. to SPARK PLUG .>