Fault code P0350 is called “Ignition Coil Primary/Secondary Circuit Malfunction” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P0350
This Diagnostic Trouble Code (DTC) is a generic powertrain code. Error P0350 is considered a general code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly depending on the model.
If code P0350 is stored in the vehicle memory, it means that the Powertrain Control Module (PCM) has detected a problem. The problem is related to the primary or secondary ignition coil circuit.
In most vehicles, an ignition system without a distributor is used, with ignition coils. In this system, each cylinder has its own ignition coil, which is connected to the spark plug with a short wire or silicone tip.
Battery voltage and a ground pulse from the PCM applied to the tightly wound induction coil creates a high-intensity spark. The spark is necessary to ignite the spark plug in each particular cylinder.
Systems that use coil blocks function in a similar way, except that multiple spark plugs are ignited from a coil block. Which ignites several cylinders in sequential order.
This type of system typically uses longer, high voltage spark plug wires to transfer the spark from the coil block to the spark plugs.
Regardless of the type of ignition system the vehicle in question has, the timing and spark operation is controlled by the PCM. When the battery voltage is constant, the ignition coil releases a high-intensity spark when it receives a pulse from the PCM.
If the PCM detects that any of the ignition coil circuits are not completed when the ground pulse is applied. Code P0350 will be stored and the Malfunction Indicator Light (MIL) may illuminate.
Symptoms of vehicle malfunctions
The main signal that an error P0350 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- Check engine control lamp on the control panel will light up.
- Jerking, jerking engine when running
- Unstable operation, ignition skips at idle.
- The engine stalls or fails to start.
- Loss of power.
Fault P0350 is quite serious, because when it occurs, it can cause problems with the engine. The engine may be unstable when accelerating the vehicle or may suddenly stall. It is recommended to diagnose and repair this fault as soon as possible.
Factors that can cause this error code
The error code P0350 can mean that one or more of the following problems have occurred:
- Short-circuited or broken ignition coil wiring harness.
- Poor electrical connection or an open circuit in the ignition coil.
- Cables and connectors leading to the ignition coil may be defective. There may be features such as wear or friction on another component.
- The ignition coil is defective.
- The engine control module (ECM) is defective.
How to fix or reset OBD-2 code P0350
Some suggested steps for troubleshooting and fix the error code P0350:
- Make sure that the electrical connection in the coil connector is good.
- If there is a problem with the motor, turn it off and disconnect the cables relating to the coil. Then start the engine with the cables disconnected and use a voltmeter. It should show a range of 5 to 20 Hz, if this range is not present, replace the ignition coil.
- If there is no signal from the PCM in the ignition coil circuit, leave the coil disconnected and check the circuit drives at the ignition coil connector. Significant voltage means a short circuit. You need to locate it and make the necessary repairs.
- If there is no voltage in the driver circuit, disconnect the connector from the PCM. And check the continuity of the driver circuit between the transmission control module (PCM) and the coil. If there is no breakage, it indicates a ground fault. Fix the problem.
- If there is a breakage, check the resistance between the ground and the ignition coil connector. The result should be infinite resistance. If not, correct the ground fault in the coil driver circuit.
Diagnose and repair of problems
The first thing to do when diagnosing code P0350 is to perform a visual inspection of all ignition coil wiring and connectors. Note if there are broken electrical connectors on the ignition coils or coil assemblies.
Also check for burned, broken or corroded wiring. The electrical connector ends of the ignition coils can also become corroded over time.
If ignition coil primary/secondary circuit codes for a particular cylinder are present, they can help identify the faulty circuit. If no cylinder-specific codes are present, you need to find out which coil output or circuit is faulty.
Once you have located the coil or circuit output, use a multimeter to check the battery voltage at the connector with the ignition on. If there is no voltage, check for blown fuses, faulty relays, etc.
If all fuses and relays are intact, use a multimeter to check individual circuits for continuity and resistance. Disconnect all associated controllers before doing this so as not to damage the sensitive electronics.
If a voltage signal is present on the ignition coil, check the connector for a ground pulse from the PCM. If the ground pulse is not present, the driver in the PCM is most likely faulty.
These are general recommendations for troubleshooting error P0350. But most often the error can be eliminated by replacing the high voltage wires and the coil itself.
On which vehicles does this problem occur most frequently
Fault code P0350 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- BMW
- Chevrolet
- Chrysler
- Citroen (C4)
- Daihatsu
- Dodge
- Ford
- Hyundai (Santa Fe, Sonata)
- Infiniti
- Kia (Sedona, Sorento)
- Nissan (Almera, Elgrand, Note, Teana, Tiida)
- Peugeot (206, 307, 406)
- Porsche
- Subaru (Legacy)
- Suzuki (Carry)
- Toyota
- Volvo
Fault code P0350 can sometimes be found with other errors. The most common are the following: P0301, P0302, P0303, P0304, P0352, P0353, P0354, P0355, P0356, P0357, P0358, P0359, P0360, P0361, P0362.
