P0352 Ignition Coil B – Primary/Secondary → Malfunction

P0352 is a generic OBD2 code.  it indicates that ignition coil “B” is has is malfunctioning on its primary or secondary side.  It is typically caused by a bad coil pack or wiring harness issue.  The first thing that you need to do when diagnosing it is to figure out if the issue is coming from the primary or secondary wiring.

The primary wiring is the wiring harness leading from the PCM to the ignition system itself.  A short, open, or poorly ground wiring harness is almost always what causes P0352 when it is the primary wiring side that has thrown the code.

The secondary side of the equation is the spark side.  Which means that plugs, plug wires (if so equipped) or the spark plug itself are causing the code.  Ignition Coil “B” indicates the problem is in cylinder 2.  You’ll need to look up which cylinder is number one on your engine.  Different manufacturers use different methods.  Here’s a pretty good explanation of how how to locate the second cylinder .  

See Also:  https://www.700r4transmissionhq.com/p0351

 

P0352 Diagnosis

 

 

P0352 Symptoms

  • Service Engine Light– The check engine light may be all that you notice when you have this code, particularly if it is caused by an intermittent wiring issue.
  • Misfiring– P0352 might be accompanied by P0302.  P0302 indicates that there is a misfire in cylinder 2.  Resolving P0352 will typically clear P0302.  A misfire can lead to a lack of power, and/or engine hesitation.
  • Rough Idle– You vehicle may idle rough if the second cylinder isn’t getting enough spark.  You  may smell raw fuel as the engine runs as well, since the second cylinder is no longer igniting fuel efficiently.

 

 

Causes

  • Wiring Issues (short, open, or bad ground)
  • Bad Coil Pack
  • Loose Connection at the coil
  • Bad PCM

 

 

P0352 Diagnosis

 

Voltage Test (Optional, but time saving)

The first place that you would want to start looking for what could be causing P0352 in your vehicle would be the wiring harness.  You can use a digital voltmeter to check if the coil pack “B” is getting the proper signal.  You would want to set it for A/C hertz and check to see if it is between 5-20hz. 

If it was between 5-20hz, it’s highly likely that the coil pack has gone bad.  Although, it could also be a bad plug or plug wire as well.  If you don’t have a voltmeter, no problem.  Just check out the parts swap method below .

 

 

Parts Swap

A great way to determine if it is an ignition related component, and not a wiring issue, is to reset the trouble code and swap the coil, plug, and plug wire (if equipped) with another cylinder.  If the misfire returns in the cylinder that you’ve just swapped your ignition components into, then you know that you are looking at is a coil, plug wire, or (most likely) coil pack failure.

If the misfire did move cylinders, you can go ahead and replace the plug, plug wire, and coil pack.  If you are on a tight budget, you can keep resetting the code and swap the ignition parts back one at a time until the misfire returns to cylinder one.  Start with the coil pack.

 

 

Wiring

If the misfire failed to move from cylinder one, then you know that you most likely have an issue with the wiring harness going from the coil pack to the PCM.  Take a look at where the harness plugs into the coil pack.  Is it damaged or loose feeling in relation to the other cylinder’s connections?  If so it may need to be replaced.

If the misfire is intermittent, go ahead and jiggle the wiring harness and see if it has an impact on the way the engine is running.  If it does start or stop misfiring, you know you’ve found your problem.  Look anywhere that the harness bends or touches anything sharp.  Check for damage and repair the wiring accordingly.

Make sure that it has a solid ground.

 

 

PCM/ECM

If you still can’t find the problem, it’s time to take a look at the PCM.  This is the least likely answer.

 

 

Conclusion:  P0352

P0352 is usually pretty easy to diagnose through the swap test, even if you don’t have any specialty diagnostic tools.  Good luck!

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