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

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What Does password P0350 Mean?

The ignition device converts battery voltage into the high voltage supplied to ignite the cylinder air/fuel mixture. The short voltage next of the mechanism is described as the major circuit. It contains the battery, ignition switch, major coil winding, a triggering system (such as a crankshaft sensor) and switching device (such together an ignition module or ECU). The high voltage next of the system is referred to as the secondary circuit. On modern-day vehicles it has the coil pack and also spark plugs.

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Current an innovation has done away with countless ignition components of the past. This includes items such as the distributor, cap, rotor – and now even the spark plug wires. Contemporary engines use only a coil pack that sits straight on optimal of the spark plug.


A coil pack


The coil pack is provided to convert the low major circuit voltage to high second voltage needed to fire the plugs. The coil pack is basically a transformer, which has coils of cable inside. The major side has a couple of hundred turns of wire, conversely, the second side has actually thousands. Present is applied to the main side of the coil, which create a magnetic field about the winding. Then, the present is interrupted by a switching device (usually the PCM). This reasons the magnetic field to collapse, inducing a voltage right into the winding. Simultaneously, the collapsing magnetic field creates a voltage in the secondary winding. Due to the fact that the an additional winding contains many much more turns of wire, output voltage is increased to thousands of volts. This is sufficient to fire the spark plugs.

The PCM to adjust an ignition coil control circuit password P0351-P0358 when it detects a problem with the ignition coil circuit. The last digit of this codes recommendations the cylinder wherein the problem is occurring. Because that example, P0351 suggests a error in the #1 cylinder coil circuit. Likewise, P0358 suggests a problem with the coil circuit on cylinder #8. Fine let the change x stand in for the critical digit transparent this article, as troubleshooting is the same for every of these codes.

What space the common causes of password P0350 ?

To amount things up, the common causes for code P0350 room as follows:

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

What are the symptoms of code P0350 ?

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

How carry out you troubleshoot password P0350 ?

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

Visually examine the coil pack and also it’s connector

The an initial still is to visually examine the coil pack and its connector. Look at for things like broken wires, corrosion, etc. Plenty of times a problem can be fixed with simply a basic visual inspection.

Swap coil packs

If you have an energetic misfire on one cylinder, swap the coil with an additional cylinder that is not misfiring. See the misfire respond to on the scan tool. If the misfire moves to the cylinder through the swapped coil, you recognize the coil is defective and not the regulate circuit. If however, the misfire remains on the exact same cylinder, you recognize the control circuit is come blame.

Test the coil

Alternately, friend can shot testing the coil v a digital multimeter. This test checks the resistance the the coil. However, this test doesn’t constantly work in identify a faulty coil. Plenty of technicians ignore it every together, however it’s worth discussing anyhow due to the fact that it’s easy to perform. Begin by disconnecting the coil connector. Affix one lead of her multimeter to each terminal top top the coil and set the meter to read ohms. This exam the coil main circuit; common readings need to be 0.4 to 2 ohms. Above the manufacturer’s repair information for the precise specifications.

Next, check the an additional circuit resistance. Carry out this by attaching one meter cause the B+ terminal ~ above the coil and the other to the coil calculation tower. Common readings should be 6,000 come 15,000 ohms. Once again, the manufacturer’s repair details should it is in consulted for exact specifications.


Testing coil resistance


Check for power

Next, inspect the coil because that power. This can quickly be done v either a test light or digital multimeter collection to volts. Disconnect the coil and touch one meter cause the B+ on the harness side of the connector while poignant the other cause ground. You must see approximately 12 volts on your meter lead. Note: on part vehicles the engine will have to be cranked throughout this test.

As in the diagram below, many ignition coils share the very same fuse and/or relay that feeds the strength supply. So, if an separation, personal, instance coil is not getting power, suspect and also open or brief circuit in the wiring to the coil. The factory wiring diagram will should be traced for additional testing.


An example of a ignition mechanism wiring schematic

(Courtesy: AllData)

Test the PCM control circuit

If whatever checks the end so far, you’ll desire to test the PCM manage side of the circuit. Recall that the PCM intermittently gives ground to the coil for preferred operation. The easiest means to check this is through an LED light or a noid light (designed for testing fuel injector control). Affix the red lead of the LED right into the B+ terminal on the harness side of the coil connector. Then, affix the black color lead the the LED into the B- terminal ~ above the connector. Have an assistant crank the engine if you monitor the check light. If the irradiate illuminates, the manage side that the circuit is good. If not, there is a difficulty in the wiring or a problem with the PCM.

Narrow this down by checking for continuity come the PCM. Set your meter come ohms and connect one result in the B- terminal on the coil connector and the various other to the coil terminal in ~ the PCM. If your meter reads OL, there is an open up somewhere in the circuit that must be repaired.

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If over there is continuity, doubt a problem with the PCM. Girlfriend can check whether the PCM is giving ground to the coil through a multimeter collection to volts. Connect one meter cause the coil terminal at the PCM and the various other to the battery hopeful terminal. Have an assistant crank the engine. You must see roughly 12 volts on her meter when the PCM grounds the circuit. If not, the PCM is most likely faulty.