Trouble CodeFault LocationProbable Cause
P0355 Ignition coil E, primary/secondary -circuit breakdown Wiring, ignition coil, ECM

We recommend Torque Pro

What Does password P0355 Mean?

The ignition mechanism converts battery voltage right into the high voltage provided to ignite the cylinder air/fuel mixture. The low voltage side of the system is referred to as the main circuit. It consists of the battery, ignition switch, primary coil winding, a triggering mechanism (such as a crankshaft sensor) and switching machine (such together an ignition module or ECU). The high voltage next of the system is dubbed the secondary circuit. On modern-day vehicles it consists of the coil pack and also spark plugs.

You are watching: Ignition coil e primary secondary circuit malfunction

Current an innovation has excellent away with numerous ignition materials of the past. This has items such as the distributor, cap, rotor – and also now also the spark plug wires. Modern-day engines use just a coil fill that sits directly on peak of the spark plug.


A coil pack


The coil pack is used to transform the low major circuit voltage to high secondary voltage needed to fire the plugs. The coil fill is usually a transformer, which has actually coils of cable inside. The main side has actually a couple of hundred transforms of wire, conversely, the second side has thousands. Current is used to the main side that the coil, which creates a magnetic field approximately the winding. Then, the existing is interrupted by a switching device (usually the PCM). This causes the magnetic field to collapse, inducing a voltage right into the winding. Simultaneously, the collapsing magnetic ar creates a voltage in the second winding. Because the an additional winding has many more turns the wire, output voltage is enhanced to hundreds of volts. This is enough to fire the spark plugs.

The PCM to adjust an ignition coil manage circuit code P0351-P0358 as soon as it detects a difficulty with the ignition coil circuit. The last digit of this codes recommendations the cylinder whereby the concern is occurring. For example, P0351 suggests a error in the #1 cylinder coil circuit. Likewise, P0358 shows a difficulty with the coil circuit top top cylinder #8. Fine let the change x was standing in for the last digit throughout this article, together troubleshooting is the same for every of this codes.

What room the common reasons of code P0355 ?

To sum things up, the common causes for code P0355 space as follows:

Faulty ignition coilProblem in the ignition coil circuitProblem v the PCM

What room the symptoms of password P0355 ?

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

How execute you troubleshoot password P0355 ?

The following steps will help you diagnose a P035x code:

Visually check the coil pack and also it’s connector

The first still is to visually examine the coil pack and its connector. Watch for things like broken wires, corrosion, etc. Plenty of times a trouble can be solved with just a an easy visual inspection.

Swap coil packs

If you have an active misfire on one cylinder, swap the coil with one more cylinder that is not misfiring. Watch the misfire counter on the scan tool. If the misfire move to the cylinder v the swapped coil, you understand the coil is defective and also not the manage circuit. If however, the misfire continues to be on the very same cylinder, you recognize the manage circuit is to blame.

Test the coil

Alternately, friend can try 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. Countless technicians overlook it all together, yet it’s worth mentioning anyhow because it’s basic to perform. Begin by disconnecting the coil connector. Connect one command of her multimeter to every terminal on the coil and collection the meter to read ohms. This exam the coil major circuit; typical readings need to be 0.4 to 2 ohms. Top the manufacturer’s repair details for the specific specifications.

Next, examine the second circuit resistance. Perform this by it is registered one meter cause the B+ terminal on the coil and the various other to the coil output tower. Usual readings have to be 6,000 come 15,000 ohms. When again, the manufacturer’s repair information should it is in consulted for specific specifications.


Testing coil resistance


Check for power

Next, inspect the coil for power. This can quickly be done through either a test light or digital multimeter set to volts. Disconnect the coil and also touch one meter result in the B+ on the harness side of the connector while emotional the other bring about ground. You have to see about 12 volts on her meter lead. Note: on part vehicles the engine will have to be cranked throughout this test.

As in the diagram below, most ignition coils share the very same fuse and/or relay that feeds the power supply. So, if an separation, personal, instance coil is not gaining power, suspect and open or short circuit in the wiring to that coil. The manufacturing facility wiring diagram will must be traced for more testing.


An instance of a ignition system wiring schematic

(Courtesy: AllData)

Test the PCM manage circuit

If whatever checks the end so far, you’ll desire to test the PCM control side of the circuit. Recall that the PCM intermittently offers ground to the coil for preferred operation. The easiest method to check this is through an LED irradiate or a noid light (designed for trial and error fuel injector control). Connect the red lead of the LED into the B+ terminal top top the harness next of the coil connector. Then, affix the black color lead of the LED into the B- terminal on the connector. Have an assistant crank the engine if you screen the check light. If the light illuminates, the control side that the circuit is good. If not, there is a problem in the wiring or a problem with the PCM.

Narrow this under by checking because that continuity to the PCM. Set your meter come ohms and connect one lead to the B- terminal top top the coil connector and also the various other to the coil terminal in ~ the PCM. If her meter reads OL, over there is an open somewhere in the circuit that must be repaired.

See more: 1 Pound Of Sugar Is How Many Cups In One Pound Of Sugar? How Many Cups In A Pound Of Powdered Sugar

If there is continuity, doubt a trouble with the PCM. Girlfriend can examine whether the PCM is offering ground to the coil through a multimeter set to volts. Connect one meter cause the coil terminal in ~ the PCM and also the other to the battery positive terminal. Have actually an assistant crank the engine. You have to see about 12 volts on your meter as soon as the PCM grounds the circuit. If not, the PCM is likely faulty.