Have a 1999 ford escort with about 226,000 miles. had a diagnostic scan done, shows p0351 code, changed the ignition coil and the car still only fires 2 spark plugs. the code says secondary circuit malfunction, ignition coil has two coils and only one seems to be igniting 2 plugs, what else can be done or changed?

p0351,p0352,p0353 and p0354. It won't start because you have four cylinders not firing . P0351 - Ignition Coil A Primary/Secondary Circuit Description: See the description for DTC P0350. Possible Causes: See the possible causes for DTC P0350. Diagnostic Aids: See the diagnostic aids for DTC P0350. Application Key On Engine Off Key On Engine Running Continuous Memory Coil-on-plug (COP) ignition testing - GO to Pinpoint Test JF . GO to Pinpoint Test JF . Coil pack ignition testing - GO to Pinpoint Test JE . GO to Pinpoint Test JE .
When you see these codes , it's time to worry . These ford coil on plug system's can fry the transistors that control the coil firing . New computer or reman at ford $ 800.00 buck's then it needs to be programmed (dealer) What engine ? 3.0 v-6
This happens when the spark plug's are neglected , gap get's to wide , make's coil's over heat an break down , spark goes through the primary wire to the computer . Your best bet , take it to a qualified repair shop.

P0351 loss of power ? That's not what this code is about . P0351 - Ignition Coil A Primary/Secondary Circuit ,you have a bad coil and possibly a bad coil driver inside the PCM . Do yourself a favor an take your vehicle to a qualified repair shop !
P0351 - Ignition Coil A Primary/Secondary Circuit Description: See the description for DTC P0350. Possible Causes: See the possible causes for DTC P0350. Diagnostic Aids: See the diagnostic aids for DTC P0350. Application Key On Engine Off Key On Engine Running Continuous Memory Coil-on-plug (COP) ignition testing - GO to Pinpoint Test JF . GO to Pinpoint Test JF . Coil pack ignition testing - GO to Pinpoint Test JE . GO to Pinpoint Test JE .
P0350 - Ignition Coil Primary/Secondary Circuit Description: Each ignition primary circuit is continuously monitored. The test fails when the powertrain control module (PCM) does not receive a valid ignition diagnostic monitor (IDM) pulse signal from the ignition module (integrated in the PCM). Possible Causes:

• Open or short in the ignition START/RUN circuit
• Open coil driver circuit
• Coil driver circuit short to ground
• Damaged coil
• Coil driver circuit short to VPWR

Diagnostic Aids: Use the 12-volt non-powered test lamp to verify START/RUN voltage at the ignition coil harness connector.
Check the coil driver circuit for open, short to VPWR, or short to ground. Application Key On Engine Off Key On Engine Running Continuous Memory All GO to Pinpoint Test JE .

From a reputable repair website:


P0351 - OBD-II Trouble Code

Auto Systems and Repair

Ignition Coil "A" Circuit Primary/Secondary Malfunction Our emissions expert has put together the following information about the P0351 fault code. We have also included diagnostic procedures you can take to your repair shop if the mechanic is having difficulty analyzing the code.
OBD II Fault Code

• OBD II P0351 Ignition Coil "A" Circuit Primary/Secondary Malfunction

What does this mean? The ignition coil or coils are responsible for igniting the air/fuel mixture inside the combustion chambers. Without reliable performance from the ignition coil(s) the vehicle will stumble and misfire.
Code P0351 indicates there's an electrical problem in either the primary ( the computer side ) or the secondary ( the spark plug side ) of the Ignition Coil "A" Circuit.
Symptoms

• Check Engine Light will illuminate
• Engine idles rough
• Engine misfires on acceleration
• In rare cases, the engine may not exhibit noticeable symptoms

Common Problems That Trigger the P0351 Code

• Defective Ignition Coil(s)
• Defective Spark Plug(s)
• Intake Manifold Vacuum leaks
• Carbon buildup in the Throttle Body air passages
• Defective Idle Air Control Valve or Electronic Body

Common Misdiagnosis

• Ignition coil(s) replaced when cause of the malfunction was a vacuum leak
• Spark Plugs replaced when cause of the malfunction was a vacuum leak

Check that vacuum lines have not come off manifold.

p0306 refers to cylinder 6 misfire detected===causes engine mechanical fault--wiring---ignition/fuel system--injector ---ECT/MAF sensor---ECM
IF there was a mechanical fault (hydraulic follower ) or valve it would be there most of the time and not just on start up. Possible injector fault but I would be inclined to check out the MAF sensor codes p0351 &2 refer to ignition coil A and ignition coil B primary /secondary--circuit malfunction === causes --wiring--ignition coil--ECM ( all causes for the both)
going on this check out the coils and check that the wiring and connections are clean and tight. basically I would be inclined to change out the coils and check /replace the MAF sensor.
change the engine --sounds like advice to get some extra money out of you.

Codes for ignition coils are not always accurate

You can get many codes for many cylinders & have one or more
bad coils

I would do a cylinder leak down test, to eliminate a mechanical
valve sealing issue

Then if all valves seal-- smoke the intake for vacuum leaks

PO301,PO351 or Coil A -- are all the same-- cylinder #1

google it or better get the FSM for your car, and read how to do the tests, that prove what causes each DTC.
505 idle speed failure.
351
http://www.obd-codes.com/p0351

there are 5 engines, so first find that out,.
351
ignition Coil # 1 Primary Circuit Peak primary circuit current not achieved with maximum dwell time.
this means the coil primary is open (other books show the fail is for too low current (open coil in COP)

505
Engine started; system voltage over 11.5v and the PCM detected an unexpected voltage condition on one or more of the IAC motor circuits for 2.75 seconds with the IAC motor active.

id fix the 351, cop coil , its probably bad, or bad connections to it.
then clean the iSC,
then reset all codes, with a scan tool
drive 20 miles or until CEL glows, driving and the rescan.

Same as Ford Escape.
P0351 - Ignition Coil A - Primary/Secondary Circuit

Cylinder #1, Pin 26 at the PCM, computer.

I would replace the coil on the plug (COP) for that cylinder and see if its' ok. If not, then it is possible that the bad coil took out the driver in the PCM. The test at Pin 26 to see if the light blinks, must be done with the correct tester or it will damage the PCM.

Hope it's the coil.

report results.

4 cylinder or 6 cylinder engine?

The computer is shutting of your fuel because no spark it is a safety feature if the fuel continues with no spark you exhaust converter could fill up with fuel the results not good.So that is why your ECM your cars computer is confederated that way.

P0351 - ignition coil section A-primary or secondary circuit malfunction.Change ignition coil.