I have a Jaguar X350 2.7 TDVi - 06 which my Jaguar specialist garage cannot fix!

It started with a turbo failure (turbine wheel axle collapsed) - something I was expecting after 250.000 km with original turbos and regular oil changes every 10.000 km. Both turbos were replaced with remanufactured units, and the intake and intercooler were cleaned from oil.

Since then, the car runs just fine, except when you floor it: after 8-10 seconds it will put itself into restricted performance mode, and P0100 + P0103 are logged.

I have access to my own IDS and when logging live data I can see that Mass Air Flow Sensor A is showing 30-40% higher values than Mass Air Flow Sensor B when putting the engine under load.

If I switch over the MAFS, MAF A will still show 30-40% higher values than MAF B.

The following has been done by my Jaguar garage to solve the problem, but with no success:

- Replaced both MAFS
- Replaced wiring between MAFS and ECU
- Replaced EGRs
- Replaced ECU
- Smoke check for leaks in the tubing

We have run out of theories now. What can be wrong? Assume that the actual airflow is 30-40% higher in MAF A - could it be that one of the turbos is operating at a higher boost pressure unintentionally? There are no fault codes logged for the turbos. Can you measure actual boost pressure with IDS?

Any help is highly appreciated - so far I have spent +£2500 on this problem, with no resolution in sight...

 

I can't find the P0100, but the list of conditions for the 0103 implies that there is a connection issue with the wires or connectors between the MAF and the ECM. Either a short or an open circuit. It also lists a bad MAF as a possible cause, but that is not you problem, since both MAFs act the same when put on the A side.

Finding it may require unplugging the ECM connector and A side MAF connector and then checking the wires for open or shorts.

 

One of the possible causes listed for P0103 is a faulty turbo so as the fault started after the turbos were replaced, I would be looking at those since you have replaced pretty much everything else MAF related that could cause the code.

 

Welcome to the forum Vektor, you should stop by our new members area and introduce yourself ==>> New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

Double posting in multiple subforums is against forum rules sorry, I've locked up that thread in the S-Type forum with a redirect to this one. Rules are rules i'm afraid.

It's funny that the code P0100 is listed in the Ford Master List as not being a Jaguar code. Furthermore P0100 is just a generic "problem with MAF circuit A" without going into detail. The P0103 is the specific code for "circuit high" and that's what you see.

I get the feeling that P0100 is triggered simultaneously as a P0101/102/103/104 so just focus on the P0103.

I agree that it's pointing to a turbo issue, probably the wastegate not functioning correctly, leading to an overboost situation on that bank = more incoming air.

Can you see how the fuelling is on that bank?

Not sure if you can see the actual boost per bank via SDD, but it's worth looking into.

I assume there is a warranty on the rebuilt turbos? I'd be going back to the supplier & asking for thier help, under warranty...

 

I thought the Jag diesel turbo didn't have a waste-gate, the variable turbine inlet vanes fulfil that function instead, but ... could it be the variable vanes are not moving correctly on one side ?

[EDIT: Yep - "The turbocharger does not have a wastegate control valve. Instead, it has variable turbocharger
vanes which are located in the turbocharger turbine housing and these direct the air flow into the
turbocharger turbine. The turbocharger vanes act as the control for the turbocharger boost pressure." ]

There is also the (inlet) port deactivation (butterfly) valves. The trio (one valve per cylinder) in each bank are each operated by one vacuum diaphram (ie one per bank). Maybe one side is operating differently to the other ?

 

I think both the Variable-vane theory and the Port deactivation theory could be plausible.

Then the question is - how do you verify if these parts are operating correctly?

 

Looking at the workshop manual the only thing that it recommends, that you haven't already included in you list of things that the agent checked is ... checking the VGT (Variable Geometry Turbocharger [I had to look that up !]) actuator, ie the guide vane actuators.

There are codes related to that;
P004500, P004700, and P004800 which all refer to the R/H bank actuator; and
P004A00, P004C00 and P004D00 which refer to the L/H bank.

As the original fault was knackered turbos, which were replaced ... I would bet a small sum that the problem lies within the new turbos they fitted (or electrical connections to them) rather than in the all the piping and stuff outside.

Is it possible to see the turbo rpms on your diagnostic device ?

 

When I read the DTC for P0103, I don't see anything turbo related. It only points to the MAF circuit. That's where I would start. Not saying it isn't the turbo, just that it would be best to start with the code.

 

Perhaps the info you are looking at is pre-TDi?

This is what my documentation says:

P0100 - Mass air flow (MAF) sensor range/performance (right hand bank)
MAF sensor circuit: high resistance
MAF sensor circuit: short circuit to ground
MAF sensor circuit: short circuit to power
MAF sensor failure
ECM failure

P0103 - Mass air flow (MAF) too high on right hand bank
MAF sensor circuit: short circuit to power
MAF sensor failure
Air leakage
Turbocharger fault <-----------------
ECM failure

 

Yep; from my copy of the Workshop Manual (2003-2009MY):

DTC
P010300

Possible Causes
Mass air flow (MAF) too high (right hand bank)
Air leakage
MAF sensor circuit: short circuit to power
MAF sensor failure
VGT actuator fault
ECM failure

 

Your's shows the 0100, which mine doesn't...so I have to bet your DTC list is correct!

And that changes my "best" guess. Always look at what was recently worked on first.

 

Hi,

Does anybody solved the problem with the MAF sensor i have the same problem on my s-type bank B is 30-40% higher than bank A

Any idea??

 

Welcome to the forum Patrick,

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

There isn't a general problem at all.

BTW you're in the wrong forum so re-post in the right one!