Nissan V35 Skyline P0350 secondary ignition issue

Nissan V35 Skyline P0350.

A customer of mine has a Nissan V35 Skyline with the 3.5-litre GQ35 V6 engine

He came in with the malfunction indicator lamp (MIL) on and after a thorough inspection of the secondary ignition we found one of the ignition coils was failing under engine load. A misfire was also noticed on a road test and the faulty coil was replaced.  Nissan V35 Skyline P0350 code was set.

The customer asked that the other five coils not be changed because they are reasonably easy to get to and to replace. The car was good for 12 months.

But then the car came back with the same dreaded P0350 fault code (ignition-coil primary/secondary-circuit malfunction). Unlike last time, there was no noticeable misfire when driving and we could not fault the coils on our lab scope. Even the spark looked good and seemed healthy.

Now I could have simply thrown a new set of coils in the car and the problem would have been fixed. However, this was not going to teach me why they all looked good yet we still had the code. Besides, we could have a feedback problem causing the engine control unit (ECU) to log this code or we could even have an ECU issue. I had to be sure why the car was logging the code and, even though I suspected a faulty coil, I was not about to just throw a set of coils at it without good reason.

Sent all of the coils to Rod Maher.

I sent all of the coils to Rod Maher in Grafton, who used his coil bench-tester to stress them out. He found two were leaking in the secondary-coil spark-plug boot. You see, Rod not only stresses out the coils but runs a incandescent test lamp that is earthed to ground – waving the pointed end over the coil boot will bring out any weaknesses the boot may have.

We replaced those two coils. I also checked them on a running engine with a spark tester set to about 35 kilovolts (kV) – using my test lamp the way Rod does – and one of the two was leaking. The other, I found out later, started to break down at 40kV when passing the pointed test lamp past the coil boot.

We cleared the code, road-tested the vehicle and retested for codes. All seemed good. The customer paid for the job and even said how much better the car seemed to drive.

But then, two days later, there was another phone call. The engine light had come back on.

Sure enough, the MIL light was on and we had our dreaded P0350 code again. This time the code would clear but reset as soon as the engine was running. There was no misfiring but it was clear whatever was setting the code was now constant and should make my job easy.

After checking each coil’s primary current and not seeing any evidence there, I retested each coil using the spark kV tester set to 40kV. Every coil passed the running test using a test lamp and did not show any leakage.

The spark plugs were only a year old but we had to rule them out, so a new set went in. There was no change.

Nissan V35 Skyline P0350 code – possible causes

• Faulty ignition-coil primary.

• Faulty secondary ignition-coil primary.

• Open secondary harness or shorted ignition-coil primary.

• Poor electrical connection of secondary circuit.

• Faulty engine-control unit (ECU).

It seemed the only thing left was to check the ECU coil-feedback signal that goes to and from the coil. If the signal was there and all was good we would then have to check the ECU powers and grounds. If they were OK then the problem would have to be the ECU.

Pico scope pattern

I hooked my scope up and checked the three right-hand-bank coils first. All voltage coil feedbacks looked the same and even voltage was going to all coils. When I repeated the test on the left bank, however, one of the feedback voltages was noticeably higher than the other five coils that had been checked.

There were two possible causes for this – it could have been a coil or a voltage leakage in the ECU. So I got out one of the old coils that we’d replaced earlier, swapped it and rechecked the voltage. This time the feedback voltage was normal. The code was cleared and did not return.



Finally, I had the confidence to replace the rest of the coils. Should I have replaced them all at the beginning? Of course I should have. That means I have to ask myself another question – do I give my customers the choice or do I take that away from them by telling them all of their coils will need replacing. In the future I think I’ll be strongly recommending all coils get replaced.

Roller Coaster BMW Maurice Donovan

Roller Coaster BMW



by Maurice Donovan

This six cylinder diesel rocked up on the back of a tow truck. I started the car and wondered why the customer called a tow truck. His complaint was that the car was blowing so much smoke out of the exhaust it covered the whole street.


After a long idle time and a short drive we were seeing oil smoke coming out of the exhaust. It was so bad that when sitting at the lights I noticed that the guy in the car behind me had his phone out videoing the smoke. I jumped out to plead with him not to dob this car in to the authorities as I was the mechanic looking at fixing the problem. He laughed at me and said it was the funniest thing he had seen – a nice-looking BMW blowing out so much smoke.

TaT’s diesel expert Clinton Brett taught me if you want to rule out the engine PVC and breathing system as being the cause of oil smoke, the easiest way is to remove the oil cap and see if the smoke disappears. So after undoing the oil cap and holding the engine RPMs up until all the oil smoke had disappeared, I left the engine idling for a long period with the oil cap off.


Then I revved up the engine and there was no more oil smoke but after I refitted the oil cap and repeated the process the oil smoke had returned. I repeated the process with the oil cap off and again there was no oil smoke.


I talked with my customer about a direction and an action plan, I made it clear there was no guarantee that this action plan would fix his problem, but it was a necessary direction so we agreed we would replace the positive crankcase ventilation valve and I would use a BG109J oil flush to help clean out the crankcase system and hopefully the car’s breathing system.


Driving around the block to allow the oil flush to work its way around and clean up the crankcase, my technician said the car started to burn more oil than ever and then all of a sudden there was no more oil smoke.


We could not believe it. We then proceeded to change the oil and filter.


I drove the car around all weekend to be sure that the problem was solved.


After showing no sign of oil all weekend, I took it for one more test drive before handing it back to the owner. The smoke had returned, after that long idle period.


I suggested we remove the rocker cover and clean out the car’s breathing system, telling the owner that I could not guarantee this was the problem, but I needed to rule out the obvious.


Removing the rocker cover entails removing the intake manifold, the injectors (always replace injector sealing washes and hold down bolts) and then the rocker cover.


What we found was a gooey, gummy, sticky mess. The intake manifold and EGR valve were also caked up with carbon. It was a big clean-up job.

Then the car would not start. After finding out my technician had not first bled the fuel system using the scan tool, we hooked up to Autologic Assist, one of the most powerful aftermarket scan tools for European cars, especially BMWs.


The scan tool bleeding process is very straightforward and after a number of goes and still only seeing 2 to 4 bars of pressure, we proceeded to check the low pressure side of the vehicle.


This vehicle runs a lift pump in the tank and it has to run at about 4 bar (60psi).  There is a low-pressure fuel sensor that transmits a voltage signal to the engine’s digital management engine control unit. The Autologic Assist scan tool parameter IDs (PID) indicated the system pressure between the electric fuel pump and the high-pressure pump was correct. There was more than 4 bar of pressure so there did not appear to be a pressure problem on the low pressure side.


We then used a clear plastic tubing on the low pressure side of the pump, to see if there was any air going into the inlet side of the high pressure pump or any air coming out of the fuel return to tank line. This test verified that there was no air in the low pressure system.


Attention now turned to the Piezo injectors

taking care to cap all openings to prevent dust entering the injector openings or the fuel rail and piping. It was beginning to look like something had entered an injector opening or maybe an injector was distorted when being removed.


All the injector pipes were removed and a small ball bearing placed in each injector feed opening. The injector pipes were then refitted and, when tightened, the opening would be totally sealed by the ball bearing.


The idea was to crank the engine and watch the rail pressure increase. The ball bearings were then removed, one at a time, while rechecking the rail pressure to reveal which injector was leaking. Obviously the injector that loses all line pressure would be the culprit.


The problem was that the Autologic Assist rail pressure PID value did not change – there was still no rail pressure after all the injector feeds were sealed.


Examined next was the flow regulating valve (FRV), the solenoid valve on the back of the high pressure pump. The FRV allows only the required amount of fuel to flow into the high pressure pump from the low pressure side in order to generate the required fuel rail pressure.


The higher the control signal current, the lower the rail pressure generated. This current to the FRV solenoid control is by way of a pulse width modulated duty cycle. Based on the fact that the higher the current the lower the pressure and therefore without current flow the maximum diesel flow would be achieved for the high pressure pump, the solenoid was disconnected.+


Still no joy – when the engine was cranked, there were still only 4 bars of rail pressure.


Now to the digital rail pressure regulating valve (DRV) located at the end of the fuel rail. For this test, the fuel return hose was disconnected. If the DRV was dumping fuel and not allowing the rail pressure to build up pressure it would be seen coming straight out of the return pile which is also at the rear of the rail. When the engine was cranked there was no sign of any fuel coming out of this return line.


Perhaps it was a faulty rail pressure sensor. Everything else was good so it could only be the sensor.


A variable resistor was used to manipulate the voltage to the signal wire. The value was adjusted on the scan tool to match the desired value of about 300 bars – still no start.


We had run out of ideas – time to call for help. At times like this the Autologic Assist team becomes the most powerful tool in the shop. Their scan tool is only part of the diagnostic package. The real strength is their team of OEM-trained technicians.


A help request was logged from the scan tool and we were soon talking with a BMW technician.


He asked that the rail pressure sensor be disconnected and then crank the engine. After a lengthy crank and still no start, the sensor was reconnected, the codes were cleared, and the engine was cranked to see what the rail pressure was doing.


To everyone’s surprise, the engine fired up.


This made no sense.


My logic tells me that on the first engine cranking, the air that would have been trapped in the fuel rail caused a low pressure code and the digital motor electronics module shut the injectors off. Even though the codes were cleared and the rail bled of all possible air, there was still no starting this car. It was only after disconnecting the rail pressure sensor and then cranking the engine that a default value was set, followed by clearing the codes, that the system came to life.


The car was starting, but oil was still burning out of the exhaust when hot.  It was obvious that the oil sludge under the rocker cover was just the tip of the iceberg and a mere sample of the state of the whole engine.


The exhaust pipe and the diesel particulate filter (DPF) were removed and it looked like the oil burning issue was in the turbos


This engine employs two turbochargers of different sizes, connected in series. The smaller charger mounted on top is capable of developing its full effect at low revs, allowing turbo-lag to be kept to a minimum. As the revs rise, the second, larger, turbo takes over.

Oil contamination was so bad , the oil sludge was a black tar that you could seal a roof
with. It gets stuck in everything and it was right through the turbos and had blocked the turbo return line.


This meant the oil that was being pumped into the turbo to lubricate the turbo spindle had nowhere to return, so it pooled in the turbo and leaked through the turbo and into the exhaust.


The smaller turbo had to be rebuilt, and the larger turbo and all the pressure and return pipes were cleaned out.


It was obvious that when the first oil flush was done, some of the blocked oil in the return pipe was dislodged, giving temporary feedback to the sump. This can explain the lack of oil smoke until days after, when the sludge moved in and totally blocked this oil return, causing the oil to pool again in the turbos and eventually flooding the exhaust with engine oil.


By now, the extent of sludge could not be ignoredand it was obvious that the crank case of this engine would be contaminated.


The sump on these engines is not easy to remove. The front all wheel drive diff shares the same case as the sump and it could be up to a 15 hour job to remove, clean and refit. The oil condition sensor that sits in the bottom of the sump was removed and it was full of sludge.


Twenty litres of a concentrated and specially formulated chemical that would dissolve this type of sludge were tipped into the engine and left for two days. The chemical was drained out and the engine filled with normal oil.


After refitting the turbos, but not the DPF or exhaust, the engine was started and let run for an hour so the bottom of the turbo could be checked for any evidence of oil.


Oil did leak out of the bottom turbo, but it was cleaned up and the engine was run again and no oil came out. More test runs and it seemed the battle had been won.


The oil was dumped from the engine, and a borescope camera showed a very clean sump. After three oil flushes and a chemical clean-out the engine was much cleaner and safer than before.


The customer was advised to bring the car back after 5,000km for another oil flush and filter service.


This story doesn’t end there. The customer took the risk of refitting the DPF, knowing how much oil had been dumped into it, and the car continued to blow oil smoke that we suspect was the residue of oil in the exhaust. The customer was advised to take the car on a long run and eventually he reported no more oil smoke and the car was running better.


This episode confirmed the need for 10,000km service intervals for diesel vehicles.

Vehicle that has an intermittent problem



In this issue’s Case Study, MD is presented with a vehicle that has an intermittent problem.  Most readers know what this is like…you jump in the car and great it plays up. Bring it into our workshop and it starts to run normal, what do we do?

In this instance we are presented with  a Japanese imported car, an early 90’s Toyota Aristo with a 2JZ-GTE engine. It had been to various other workshops before it was brought to me by a frustrated customer.

We found access to data information on this import difficult to source, to add to this our scan tools would not communicate with this car.   So as usual we started with the basics.

So, now that we have experienced the problem on the test drive,  our next step is to carry out a visual and in doing so it was discovered the cam sensor plug is badly broken and the sensor terminals were covered in oil. Not a good recipe as oil attracts moisture and moisture acts as a contactor which no doubt will short out the sensor.


When the customer picked up his car, he could not believe the difference in the way this car drove, and he was ecstatic that we nailed this problem. He had sent his car to numerous workshops in the past without a fix when in reality, all we did was start with the basics! We now have another customer who will recommend us to others!


So, in summary it is always important to cover the basics, and while checking these basics we often notice visual items of concern.


In fact we find a lot of problems can be sorted out and found on our initial visual checks when we are presented with a problem car. Always be mindful we can actually have a mechanical integrity issue in the engine and that’s in, low compression or maybe a cam timing retard problem. So never rule out the basic when dealing with a modern car with a driveablity issue.

GDI Gasoline Direct Injection

GDI Gasoline Direct Injection


The article below is from our colleagues in the US, namely Fixed Ops Magazine. Once again it reflects the growing problem of carbon build-up and deposits in the intake system which is causing performance problems.

Gasoline Direct Injection (GDI), also known as Petrol Direct Injection or Direct Petrol Injection or Spark Ignited Direct Injection (SIDI) or Fuel Stratified Injection (FSI), is a variant of fuel injection employed in modern four stroke

GDI systems allows a combustion engines to run an ultra-lean condition, therefore this will improve fuel consumption, decreased combustion temperature, and improve emissions.

Unfortunately there are side effects caused by the lack of fuel that once washed down the cylinder walls and cleaned allot of the carbon away.   While technology has taken enormous steps in improving combustion burning and fuel efficiencies, it has not been able to combat the side effects that are left over after combustion.

It seems the more that technology improves combustion burning the greater is the problem we the technician are seeing from this left over carbon that is messes with the driveability of our customers cars.

Most of us know the value of a bore-scopes and no doubt this article demonstrates another value on the use of a bore-scope that can be useful  for techs to back-up your carbon build-up suspicions of a badly carbon intake system.  There is no easier way than using this type of tool to not only confirm a carbon issue but it is a powerful way to reassure your customer the need of a carbon clean treatment for their car’s intake system.


Many modern vehicles are powered with GDI Gasoline Direct Injection

Choice of Repairer campaign

The voluntary agreement for the Consumer Choice of Repairer campaign lead by Stuart Charity from the AAAA (Australian Automotive Aftermarket Association) has been signed. Technical information sharing



In the aftermath of what appeared on the surface to be a great win for Australian car owners and the aftermarket industry which looks after their vehices, many industry experts remain sceptical that workshops may not get the promised full sharing of manufacturers’ technical information – one of the keystones of the Choice of Repairer campaign launched by the Australian Automotive Aftermarket Association (AAAA) in 2009.

One Queensland workshop owner who has been following the negotiations closely is MTA committee member and TaT technical advisor Maurice Donovan, who spells it out very clearly – Australian aftermarket workshops will be short changed if the industry does not achieve the same level of data sharing now operating in Europe and the US.

As fast as new car industry officials in Australia claim that the aftermarket already has access to the data it needs, Maurice shoots them down in flames, citing actual case studies in his own workshop where he was denied information to enable him to professionally repair his clients’ cars.

While the agreement, signed in front of federal Minister for Small Business Bruce Billson was indeed a great win for the AAAA campaign, Maurice is worried that the devil will be in the detail of the agreement.

The voluntary agreement, signed in December by the five organisations representing the key industry and consumer groups, is considered to be the forerunner to making vehicle data sharing a reality.

‘This agreement on access to service and repair information ensures independent repairers can access all information required for the diagnosis, body repair, servicing, inspection, periodic monitoring, and reinitialising of the vehicle, in line with the service and repair information manufacturers provide their authorised dealers and repairers,’ said AAAA Executive Director Stuart Charity.

TaT, along with Maurice Donovan, shares Stuart’s excitement and congratulates him for his tenacity and negotiating skills which have achieved this necessary breakthrough. But the signed agreement contains no detail, and is really just an agreement to agree that something should be done.

As Maurice says, ‘This is a good start. A little thin on the detail and the only reference that I found that specifically refers to programming was the word ‘initialisation’, which is a little vague.

‘That could simply mean the sequences to manually initialise and may not cover scantool programming or access to digital data for calibration updates. The specifics need to be clarified,’ Maurice added.

Stuart Charity is playing the game very carefully, acknowledging that nobody should be under any illusion that the fight is over. ‘It has really just begun’, he said.

‘What we ended up with was not an agreement we would have drafted ourselves, however it’s a lot more than we had previously, and provides us with a very solid foundation to move foreward.

‘The parties have agreed to give Australian vehicle owners rights similar to those enjoyed in Europe and the US. The accord creates a level playing field enabling independent aftermarket workshops to compete with the car company authorised dealerships.

‘The agreement is a win-win-win for all parties. It promotes consumer choice for owners of 17 million vehicles, particularly those in regional areas where there are fewer dealerships. It helps 22,000 small workshops remain in business and the vehicle manufacturers will earn a fair price for the data that they share,’ Stuart said.

Parties to the agreement also acknowledged that the emerging vehicle telematics technologies enabling increased transmission and use of data relating to vehicle use, performance and diagnostics present emerging challenges for all stakeholders. To address these challenges, the parties will implement a process to develop protocols relating to vehicle data access and ownership with progress to be reported in 12 months.

Until the agreement is put into practice, independent workshops will remain unsure about how much technical information they will be able to access or buy to enable them to perform the tasks necessary to get their customers’ cars on the road, without being forced to do it via a dealership garage.

As Maurice Donovan points out, ‘There are so many holes in the availability of technical information, OEM tooling and software updates. We have to struggle constantly to get the right information we need, even for Australian vehicles.

‘One of the reasons we at TaT keep stressing the need for technicians to constantly learn about new technologies is that it will only be through stockpiling our knowledge that the aftermarket will survive.

‘If automotive repairers do not knuckle down and study and at least try to keep up by continuing to be trained, many of them will not be employable in our industry in the near future.

‘The new car manufacturers know this and I suspect they are banking on us gradually falling by the wayside, and they will then have the monopoly they have always wanted. Why are dealerships so hell bent on offering ridiculously low fixed price servicing? They know if technology will not get rid of us, perhaps pricing will,’ Maurice added.

‘What they do not realise is that we are a resilient lot of stubborn old farts who will not give up without a fight. But I firmly believe that knowledge is the powerful weapon that can penetrate the stronghold of those big companies who think they can walk all over us.

‘I don’t directly blame our local dealerships for the current adversorial climate. It is not entirely their fault that the aftermarket cannot source the information it needs to fix cars. The pressure is surely coming from the big end of town, like the manufacturer organisations, the new car franchises and the associations representing the dealerships,’ Maurice added.

As Stuart Charity has constantly pointed out, the aftermarket will be expected to pay for the same information available to dealerships, but how this will pan out among workshops is yet to be discovered.

And TaT director Jeff Smit says, ‘Many small independent workshops will not be able to afford to buy all the information they need to cover all makes of cars that go through their workshops. However, I can see many workshops specialising in just one or two makes of vehicles, and I can also see a big increase in the number of highly specialised roving technicians who will invest in the knowledge and the tools for modern vehicle maintenance and workshops will hire them as consultants as required.’


Excessive Fuel Consumption

Check List for Excessive Fuel Consumption

Often a customer will state that their vehicle appears to be using excessive fuel. Over the years I have created a Check List as to what could be causing such a problem. I call this my list of  Intensive List Of Possibilities.

We have different procedures for many scenarios we see in our workshop. My list is a “work in progress” as many things change in the world of diagnostics.

These procedures helps to keep us focused and uniformed when doing diagnostic investigation research on our customers’ vehicles. It also gives us something to show our customers when a car is brought into us  which allows us to justify a necessary diagnostic charge before starting a job.

Before starting, check with the customer and obtain at least the last 3 fuel consumption figures. Ensure to enquire from the customer how much driving has been city driving and how much highway driving. Look up the factory standards for fuel consumption for this vehicle and insure there is actually an excessive fuel consumption issue.


Do a visual check; see if there is a rich smell or black smoke from the exhaust tail pipe. Scan check vehicle for codes and check live data for clues, pay close attention to fuel trim readings and insure that the O2 sensor is oscillating between rich and lean and is not slow. This must be checked at all the rev ranges.

If nothing has stood out to indicate a rich mixture, set up our portable gas analyser and road test.

After this we can be sure the vehicle is not necessarily running rich and the below steps need to be examined.


1              Missing or defective thermostat, causing low operating temperature:

2              Clogged intake manifold exhaust crossover passage (for heating intake manifold):

3              Engine misfire caused by bad spark plug, ignition wire, coil, dist. cap or rotor:

4              late ignition timing:

5              Defective oxygen sensor (causes rich mixture) (should have already been checked)

6              Defective coolant temp. sensor for engine computer.

7              Worn timing belt or chain (may cause rich fuel mixture in fuel injected cars with a MAP sensor):

8              Incorrect timing belt installation (timing marks should line up):

9              Dirty air filter:

10           Clogged or defective PCV valve:

11           Incorrect valve clearance (especially if too tight):

12           Worn valve guides (makes fuel mixture too lean at low power):

13           Vacuum leak: Smoked test

14           Dirty fuel injectors or leaking fuel injectors:

15           Bad fuel pressure regulator:

16           Bad MAP sensor for fuel injection:

17           Bad or dirty MAF meter:

18           Leaking intake duct between air flow sensor and throttle body:

19           loss of compression pressure due to worn rings or leaking valves:

20           Exhaust backpressure caused by clogged catalytic converter,

21           Binding brakes:

22           Leaking evap purge valve:

23           Wrong oil velocity:

24           Low tyre pressure:

25           Have the wheel properly balance/aligned:

26           Alternator uses power from the engine to replenish the lost battery voltage, which adds up       to increased fuel consumption:

27           Driving habits and environments play a significant role in fuel economy:

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