Jeep, Low oil viscosity fault code

[anglia4]

I’ve got a 2012 Grand Cherokee WK2 3.0 crd.

Last week it threw a check engine light, fault code p1d30, which google tells me is “low oil viscosity”.

So yesterday I changed the oil and filter, and then drove about 4km into town and parked. When I started it up again, the check engine light was back on, with the same code

Does anyone know what can cause this fault code?

and, how does it measure it? 
 

4km of driving doesn’t feel like enough time for the oil viscosity to be genuinely altered, so I’m wondering if it might be a faulty sensor, or some other issue.

[AllTorque]

Any other codes or lights on the dash. Is the oil level perfect (do not overfill). Oil gets diluted by diesel when it does a dpf regen. It should evaporate after some hot (highway) driving.

[Sunbeam]

1 hour ago, anglia4 said:

I’ve got a 2012 Grand Cherokee WK2 3.0 crd.

I found your problem ^

Happy to give more tech tips anytime.

[anglia4]

30 minutes ago, Sunbeam said:

I found your problem ^

Happy to give more tech tips anytime.

Valid

[anglia4]

1 hour ago, AllTorque said:

Any other codes or lights on the dash. Is the oil level perfect (do not overfill). Oil gets diluted by diesel when it does a dpf regen. It should evaporate after some hot (highway) driving.

Yeah google had filled me in on this.

And I think it may have been doing a regen when it first threw the code as I stopped and got out of the car to pick something up and all the fans were going hard, for seemingly no reason, a few minutes before the light came on.

i thought changing the oil would have taken out the diesel though?

It doesn’t get highway driven often these days so I might take it out for a run this afternoon. Would half an hour be enough?

[AllTorque]

Should be. Do you have a scan tool?
The reason I ask about the oil level is this may be how the fault code is triggered. Diesel diluted oil will raise the oil level.

[johnnyfive]

Might need to tell the ECU you've changed the oil? So it knows where its starting point/level is?

I have 0 experience of these, but is it possible that there is some kind of calculated counter, like what the ECU thinks the theoretical oil viscosity might be, after XX number of regens & driving conditions? 

Some kind of counter, relearn, or reset required? 

Again, just theorizing. 

[mjrstar]

Can you scan it to check dpf pressures or % blocked on the dpf? Even egt's might give an idea.

There might be a calculation that if it fails a regen due to dpf blockage not reducing it decides that extra fuel has ended up in the oil.

 

Take it to mexico. A pull a day keeps the dpf light away.

 

In my diesel the parameters for passive regen are over 1/2 tank of fuel, up to operating temp and >2000rpm. It probably needs 15 minutes or more at a guess.

[anglia4]

My scan tool seems to be too basic to feed me that much info.

Annoyingly, the 2011/2012 jeeps, as far as I know, can only have the oil change counter reset with a proper tool. I’ve had the “oil change due” warning on startup for the last 50,000kms…

[AllTorque]

That could be a factor to your fault code

[keltik]

Another brand I won't mention throws "engine oil deteriorated" codes if it calculates low oil viscosity. 

The calculation is based on engine oil pressure vs temperature vs rpm.

So a slightly blocked oil pump strainer = lower oil pressure = fault code when the viscosity is actually ok and the oil pressure is high enough that it won't trigger other oil pressure related fault codes.

[anglia4]

Alrighty. My bluetooth OBDII tool arrived from China the other day, so I've been able to get a bit deeper into things.

So it definitely appears that the oil viscosity code is more than likely being caused by the DPF, and that I really need to take it for a big long drive. I have also reset the oil change counter, so we can rule that out now.

To complicate matters though... yesterday I got the Electronic Throttle Control light come up on the dash, which comes with a limp mode effect where it won't let me have most of the engine torques. So I'm not sure if it will do the DPF burn while that light is on

I can't find a specific code or module related to that on JSCAN, but did find some other interesting codes hiding deep in the tool:

It appears that one of the O2 sensors is unplugged or faulty.

I asked Jeeves if this could cause the ETC (Electronic Throttle Control) fault, and it said yes it could mess with the calculations and put it into fault mode.

So I'm going to start by checking the 02 sensor and see if I can solve that one.

Any suggestions are welcome! I have no idea what I am doing.

[anglia4]

Jeeves says it absolutely will not do a DPF burn while the ETC light is on.

[mjrstar]

You might need to remove the dpf for a manual cleaning if it's been persisting for a while.

[Alfashark]

Yeah, get it out and give it a manual clean then reinstall.  Clear codes and then start making some phonecalls for pricing of a DPF-ectomy and relevant coding to make sure the ECU thinks everything is sweet.  Get an EGR delete + coding done at the same time and you'll be set for life.

[anglia4]

What are the relevant legalities around making the EGR and DPF go away?

[AllTorque]

EGR no rules. DPF if first registered before 2010 can delete. Post 2010 can be legal with an emissions test.

[anglia4]

So how would one go about cleaning the DPF?

[440bbm]

30L of petrol in the cab and a long wick should about work?

 

 

best things is to send it to the profeesional cleaners.

 

or cut it out and get it tuned to remove the dpf stuff in the ecu. there are a number of specialists that do this. seems the best scenario

[Doug Hill]

11 hours ago, anglia4 said:

So how would one go about cleaning the DPF?

Lots of dpf cleaner products out there. Have used a wurth one a vehicle without removing the dpf with some success 

Most diesel specialist shops can clean the DPF in a hot tank. 

 

Edit - removing the dpf doesn't offer any performance advantage over having a tune anyway, but it will make it stink like shit, so if you park in a garage you might begin to hate your car every time you start it.