Hi

Bought a Bentley continental GT (2004). Has come up with an injector 2 fault and a clutch solenoid p0741 fault.

The issue with the car was jolting a bit at idle. Misfires at random pts and gear 2,3 and 4 no revs beyond 3000rpm and not moving up a gear. So would lift foot off accelerator and it would move up to the next gear. Fine at gear 1,5 and 6. Started off only happening in mornings but happens more regularly now.

Any chance injector 2 and 3000rpm issue are linked or is p0741 just a completely seperate issue?

thanks

 

So a couple of questions.

1. What was the actual fault code for the #2 injector? Was it a P0202? Or other P-code?

2. Which code is listed FIRST and which code SECOND? In other words, when you scanned for faults (and which device did you use?), was the P0741 first to show with the injector code listed second? Or the other way around? I'm going to guess the injector code first, trans code second.

P0741 is a pretty serious fault code. Essentially the torque convertor is not locking up 1:1 with the trans. There are several reasons this could be, some of which are:

• Faulty TCC
• Faulty torque converter lockup solenoid
• Internal short in the TCC solenoid
• Wiring to the TCC solenoid that is damaged
• Faulty valve body
• Faulty Transmission Control Module (TCM)
• Faulty Engine Coolant Temperature (ECT) sensor
• Damage of the wiring harness to the transmission TCM
• Restricted hydraulic passages from dirty transmission fluid

The ZF 6HP trans is well known in the transmission world. My suggestions is take it to a transmission place that can service a 6HP and have it further diagnosed. Given the mileage you have on the 2004, the trans fluid might never have been changed, and this doesn't preclude the possibilities listed above about the Torque converter and TCC.

But, tell me more about what you meant by #2 injector fault. Need a P-code.

 

Thanks for the repose.

Correct it is p0202 for the injector. Not sure what order they came in as the garage did the diagnosis. I have had the RAC breakdown do diagnosis when the fault started and the 0741 code never appeared but equally neither did p0202. Originally the attached codes appeared but then disappeared once a couple of leaking pipes were resolved. Since then it has been these 2 codes coming up. You are right transmission fluid hasn’t been changed for ages per the history so could be that but equally I thought could be a chance linked to injector given cane on at similar time?

 

Personally I thought 0741 may be coming on because I was effectively lifting my foot off the accelerator to trick the car to jump gear when maxing at 3000 rpm given that may be limp mode?

looking at the history it has had some transmission fluid topup in the last and hence may be low. Where is the transmission fluid tank located in order for me to check level?

thanks

 

I had multiple misfires which turned out to be the cables running to the injectors had hardened with the heat and the insulation had cracked causing shorts.

 

First of all, take Steve Lowes advice seriously and is relatively inexpensive but could be a long exercise. On an 04 and based on its history, where it's been, pipes and wires are vulnerable and often the cause of failures that point to sensors. But the extra challenge here is these sensors are all likely old too making diagnosis a little bit more of a challenge.

That said, lets concentrate on the list of codes you posted in #3. In diagnosing this sequence, and I am assuming the shop that produced it just deleted these to see if they came back? Instead, you now get a P0202 and P0741? If you delete these two codes they come right back? Do I have that right?

In looking at the list of codes in #3, at a glance, I would concentrate on two and put aside the rest for the moment. The two serious codes you have are:

18047 and 17576

These two codes and the source of failure that caused them probably caused all of the rest of the misfires including the multiple misfires. It is a coin toss which one of if both are the culprit, but lets take them one at a time. BTW, both are serious faults and could cause limp mode which is what you might be seeing now in the P0741.

18047 - This platform is a drive by wire. There is no physical/mechanical connection between the accelerator pedal and the throttle bodies. Instead, the pedal uses a sender unit and sends a range of voltage signals in the 5v range that receivers in the TBs pick up. Motors in the TBs then set the butterflies in positions to match commanded throttle. 18047 essentially reports that this signal went completely out of the expected range (probably momentarily). Since this is an extremely serious signal (you can't have the engine in an RPM range you didn't command via accelerator pedal) the EMS will instantly default to limp mode. The pedal sender works like a rheostat and a simple signal dropout that is intermittent can set all of this limp mode in motion. You might see this again, and if you do, you'll probably need to replace the accelerator sender unit or wiring could be at fault.

17576 - This is also a serious fault. It reports the Bank 2 MAF has either failed or wiring to it is the problem. BTW, all of the misfires are the cylinders from bank 2 and this is bank two MAF. The misfires are likely all false and were reported as a result of the MAF failure bank 2. Also BTW, MAF wiring issues and MAF failures are pretty common and another recent long thread just addressed a similar problem. The MAFs are a primary input to the fueling algorithm, as such, if the MAF quits sending a signal, even momentarily can set a limp mode.

Combining all of this including the first list of codes, along with the recent P0741 code, it could (but lower probability) be a bad ECU or wiring in and out of the ECU especially given this is an 04. The weird shifting you described in your first post now sounds more like limp mode.

And a note: just ignore 18331 (ALWAYS). This is not a fault of any kind. it is only a pointer that shows up in Address 01 (ECU 1) to direct the diagnosis to address11. It goes away when the real faults are corrected.

Where to start - the first place I would start is right where Steve suggested. Look at all wiring and connections you can reach including in and out of the ECUs. Is there any evidence of water ingress around the ECUs as this was a common cause of failures in early series 1 Continentals. Do this exercise first, then delete all codes and start over. See what returns.

Sorry for the "stream of consciousness" here. Too early and low of coffee at the moment.

 

Hi

thats correct they deleted the codes and now just these 2 codes exist. The intermittent accelerator pedal has stopped showing up 18047. The fact it is now showing injector 2 there must be merit I getting that changed right? Does injector 2 also sit in bank 2 or bank 1?

the only other weird thing that happens is when I take the car on a long run on a motorway for 10 mins, when I stop at lights there is smoke coming out from under the bonnet. It’s had a coolant leak in the past and smells like that so could just be residual coolant or could this be as a result of transmission fluid or injector 2? Smoke is light blue and has a burning odour similar to coolant leak smell. No leaks when I switch off the car and park it.

thanks

 

Also since we sorted the leaking vacuum hoses all the MAF and cylinder codes have gone including accelerator pedal. So really just these 2 to focus on given I have done 30 miles on the car and the previous codes have not reappeared.

Thanks

 

I haven't addressed injector 2 as it is on the opposite side Bank 1 and should be unrelated to all of this, unlikely the cause of the P0741. If it is repeating then look at it. Check wiring to the injector, but also likely it is a stuck or dirty injector. Unfortunately, if one bad old injector is found the rule is replace them all with new for good balance. The burning fluid is not good. Usually blue is petroleum. If trans is leaking, oil could be burning up on exhaust and under drive pressure so doesn't leak when parked. You probably need to get it up on a lift and look at the trans, or have a trans shop do the P0741 diagnosis and repair recommendation.

Here is a cylinder layout for the W12:

 

Good, then skip the first fault code list. Vacuum leaks will do that and also common in your MY. Then now I would see two unrelated faults.

 

Thanks

I’m going to try and change injector 2 given I’ve ordered. Hopefully that gets rid of the jolting at idle and p0202 code. Is it an issue if I don’t replace all injectors together? If injector 2 that may be the cause of the jolting in power years as presume bank 2 only kicks in at higher gears, which is where I don’t have the shift issues.

then will get transmission fluid looked at. Has had a couple of topups over the past couple of years which suggests there may be a leak somewhere. So best to get that checked out as a seperate issue.

Thanks

 

Hello Dav,
What do you mean by "bank 2 only kicks in", your model year is not a cylinder deactivation setup, meaning it does not run on 6 cylinders then 12, all 12 cylinders are always active, W12 cylinder deactivation did not come in until 2015 or 16 I believe.

 

Ah ok. Thought that could be the only rational reason why limping in lower gears.

Thanks

 

Also, if it was a later model, DOD does not shut an entire bank down. The engine would be so out of balance it would shake itself to death in a matter of minutes. DOD, shuts down select cylinders on each bank. It has to match the firing order with every other cylinder in the sequence deactivated, as an example.

 

Hello BWings,
Actually it appears that the 2016 W12 dose shut down just 1 bank of the engine, the left side.

See videos.




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