Trouble CodeFault LocationProbable Cause
P0350 Ignition coil, primary/secondary -circuit malfunction Wiring, ignition coil, ECM

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What Does code P0350 Mean?

The ignition system converts battery voltage right into the high voltage used to ignite the cylinder air/fuel mixture. The low voltage side of the mechanism is described as the primary circuit. It includes the battery, ignition switch, primary coil winding, a triggering device (such as a crankshaft sensor) and switching device (such as an ignition module or ECU). The high voltage next of the device is referred to as the secondary circuit. On contemporary vehicles it consists of the coil pack and spark plugs.

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Current modern technology has done away with plenty of ignition contents of the past. This has items such together the distributor, cap, rotor – and now even the spark plug wires. Modern-day engines use only a coil fill that sits directly on height of the spark plug.


A coil pack


The coil fill is supplied to convert the low major circuit voltage to high second voltage required to fire the plugs. The coil load is basically a transformer, which has coils of cable inside. The primary side has actually a few hundred turns of wire, conversely, the an additional side has actually thousands. Current is applied to the main side of the coil, which create a magnetic field around the winding. Then, the existing is interrupted by a switching maker (usually the PCM). This causes the magnetic ar to collapse, inducing a voltage right into the winding. Simultaneously, the collapsing magnetic field creates a voltage in the second winding. Due to the fact that the second winding has many an ext turns the wire, calculation voltage is raised to hundreds of volts. This is sufficient to fire the spark plugs.

The PCM to adjust an ignition coil regulate circuit password P0351-P0358 as soon as it detects a trouble with the ignition coil circuit. The last digit of these codes referrals the cylinder where the concern is occurring. For example, P0351 indicates a error in the #1 cylinder coil circuit. Likewise, P0358 shows a difficulty with the coil circuit on cylinder #8. Fine let the change x was standing in for the critical digit throughout this article, as troubleshooting is the very same for every of these codes.

What room the common causes of password P0350 ?

To sum things up, the common causes for password P0350 room as follows:

Faulty ignition coilProblem in the ignition coil circuitProblem v the PCM. PCM difficulties are the the very least likely cause. Some Ford cars, such together the 3.0L Ford fusion and Ford to escape were known to have actually faulty PCMs.

What are the symptom of password P0350 ?

In enhancement to one illuminated inspect engine light, the most usual symptom is an ignition misfire. Often, P035x codes will likewise be attach by a misfire password (P0300-P0308).

How carry out you troubleshoot password P0350 ?

The complying with steps will aid you diagnose a P035x code:

Visually inspect the coil pack and it’s connector

The first still is come visually inspect the coil pack and also its connector. Look for things like damaged wires, corrosion, etc. Countless times a difficulty can be fixed with simply a an easy visual inspection.

Swap coil packs

If you have an active misfire on one cylinder, swap the coil with an additional cylinder the is no misfiring. See the misfire respond to on the scan tool. If the misfire move to the cylinder v the swapped coil, you know the coil is defective and also not the manage circuit. If however, the misfire continues to be on the very same cylinder, you know the manage circuit is to blame.

Test the coil

Alternately, friend can try testing the coil v a digital multimeter. This check checks the resistance of the coil. However, this test doesn’t always work in determining a faulty coil. Many technicians disregard it all together, but it’s worth discussing anyhow because it’s straightforward to perform. Begin by disconnecting the coil connector. Affix one command of your multimeter to each terminal top top the coil and set the meter to read ohms. This tests the coil primary circuit; common readings should be 0.4 come 2 ohms. Consult the manufacturer’s repair information for the exact specifications.

Next, inspect the an additional circuit resistance. Execute this by it is registered one meter cause the B+ terminal on the coil and the other to the coil calculation tower. Common readings need to be 6,000 to 15,000 ohms. When again, the manufacturer’s repair info should it is in consulted for specific specifications.


Testing coil resistance


Check for power

Next, check the coil because that power. This can conveniently be done with either a test light or digital multimeter set to volts. Disconnect the coil and touch one meter result in the B+ ~ above the harness side of the connector while touching the other lead to ground. You have to see approximately 12 volts on your meter lead. Note: on some vehicles the engine will have to be cranked throughout this test.

As in the chart below, most ignition coils re-publishing the same fuse and/or relay that feeds the strength supply. So, if an separation, personal, instance coil is not obtaining power, suspect and also open or quick circuit in the wiring to that coil. The manufacturing facility wiring diagram will must be traced for additional testing.


An instance of a ignition mechanism wiring schematic

(Courtesy: AllData)

Test the PCM regulate circuit

If whatever checks the end so far, you’ll desire to check the PCM manage side the the circuit. Recall that the PCM intermittently supplies ground to the coil for preferred operation. The easiest means to test this is v an LED light or a noid light (designed for experimentation fuel injector control). Affix the red command of the LED into the B+ terminal top top the harness next of the coil connector. Then, connect the black lead of the LED into the B- terminal ~ above the connector. Have actually an assistant crank the engine while you screen the check light. If the irradiate illuminates, the regulate side that the circuit is good. If not, there is a difficulty in the wiring or a difficulty with the PCM.

Narrow this down by checking for continuity come the PCM. Collection your meter come ohms and connect one cause the B- terminal top top the coil connector and also the various other to the coil terminal at the PCM. If your meter reads OL, there is an open somewhere in the circuit that need to be repaired.

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If over there is continuity, doubt a problem with the PCM. Girlfriend can inspect whether the PCM is giving ground to the coil with a multimeter set to volts. Connect one meter bring about the coil terminal at the PCM and also the various other to the battery confident terminal. Have an assistant crank the engine. You must see around 12 volts on your meter as soon as the PCM grounds the circuit. If not, the PCM is likely faulty.