Faulty MAF Sensor in a Series 3 Diesel Auto D40

Here's some info on the MAF sensor. I drive a series 3 diesel auto D40 which is relevant as they have a DPF. Its a long read but worth the effort (IMO).

The Story...

On Monday afternoon 10 kms into Victoria and towing a 1200kg trailer my DPF light comes on. My DPF has been deleted, so it could not have been blocked and needing to be 'regened'. Unsure what to do and with scratchy mobile signal I continue on thinking (praying) that the light will go out.

I arrive into Ouyen with the light still on and knowing I really do have a problem. I called Old.Tony who preceeded to try and assist me for the remainder of the day (mainly because we had a meeting scheduled for later in week which he wanted me to keep ).

I decide to return to Adelaide (400 kms away). Along the way both Tony and the 'real' boss Miss Piggy seperately determine that the fault could be the MAF Sensor. 150 kms out the ute went into Limp Mode. I unsucessfully reset the ECU three times but it wouldn't go out of Limp Mode.

I drive 50kms in Limp Mode. Tony and I decide it MUST be the MAF Sensor that is stuffed. So I pull up under a roadside light and unplug the MAF sensor reset the ECU and plug the MAF Sensor back in - no luck.

I drive the remaining 100 kms to Adelaide in limp mode. It was damn frightening pulling a trailer at 15KPH up hills in fog and rain with trucks flying by at 100KPH. I got to 83KPH down hill lol

The Outcome...

It was the MAF Sensor and in series 3 diesel auto's the DPF light comes on when the MAF sensor is faulty. The ECU WILL NOT reset with a faulty MAF sensor and the service manager at my dealer told me yesterday a DPF needing a regen will also not allow the ECU to be reset - is that correct?

The logic for throwing the DPF light is that a buggered MAF sensor plays havoc with the DPF and if you drive it in limp mode it will burn out the front DPF temp probe - which happened with me. I guess Nissan also never though anyone would drive their D40 with the DPF warning light on until it goes into limp mode and then continue to drive another 150 ks in limp mode! I can also confirm that the fuel economy in limp mode is dreadful!

All was covered by warranty which was good news (a MAF sensor is $400). The service manager also told me that when they finally reset the ECU and got it restarted it blew black soot throughout the entire workshop. Every car had to be washed the apprentice had to sweep the entire floor lol.

That's what you get with no DPF and driving for 150kms in limp mode running rich. lol

Key Message...

We need a better way off determining whether the MAF sensor is functioning properly than just an amber coloured dash light linked to a dreadful piece of technology known as a diesel particular filter.

BH

Sounds like one hell of a trip. Most of the Patrol guy's carry a spare MAF and the correct torx bit to remove it as part of their normal spares kit. Maybe Navara owners will have to do the same as well??

Leprechaun said:

Sounds like one hell of a trip. Most of the Patrol guy's carry a spare MAF and the correct torx bit to remove it as part of their normal spares kit. Maybe Navara owners will have to do the same as well??

Click to expand...

Makes sense but it also ties up $400.

You can buy MAF cleaner for $25. Again this is more of a Patrol fix, the MAF on the ZD30 are renowned for getting covered in oil from the blow by and subsequent over fueling from incorrect readings This was the main cause of the grenade going pop.

Was there anything obviously wrong with yours?

On the D40 the MAF sensor sits a few cm away from the air box and the PCV enters a fair bit further downstream. If the PCV is working, the engine's turning over and air is being sucked away from the MAFS - which means in the D40, the MAFS is safe from contamination.

I have the answer for MAFS data, came with my new phone and what I thought was a dodgy bluetooth OBD adapter.

I recently bought a Samsung Galaxy SII which runs Android and have been playing silly buggers with it and discovered this gem in the Andoid Market - Torque by Ian Hawkins - it just happens to work with my cheap (about $50) bluetooth adapter which is an ELM327 thing out of Hong Kong. Jason pointed me to mine in this post.

This is a BRILLIANT product. Cost me $4.52 at the time. I've customised the gauges so this is what I get to see while driving:


Top left is the MAF readout. I'll know if it's stuffed now! I keep an eye on voltage - no idea why, it's always good at 14.6 or so. I watch the throttle because when the torque converter is locked, if I exceed 50% throttle it will unlock on me. Middle row on the right is a bloody working turbo boost gauge so now I don't need to go buy one!

The last two are water temp and kilometres per litre. It's actually fairly accurate - my goal is to get the average over 10, but on the tyres I have that won't happen.

If you have an Android phone, check out that app.

and the service manager at my dealer told me yesterday a DPF needing a regen will also not allow the ECU to be reset - is that correct?

Hi BH
Yes I believe this is true.
U can usurp the REGEN by making sure your sensor values are correct then continue to run in limp mode-- it should eventually return to normal. It might take 30 klm or more, the computer will see this as a regen and recognise the correct values to enable unlocking of limp mode.http://www.navara.asia/images/smilies/rant.gif
U should have seen a fault code if U overheated your DPF temp sensor (0428 or close to it).
The MAF is probably connected into the emission control side of things if it brings up the DPF light.
Give me a ring
Rd's
Burgo

Anyone know of an equivalent app for iPod touch or iPad?

Regards Murph

Scubamurph said:

Anyone know of an equivalent app for iPod touch or iPad?

Regards Murph

Click to expand...

Yes Scuba - its called DashCommand (V2.7.0 is NOW released). Its a $59.95 download thru iTunes and from the research I have done its excellent. It can read everything and anything that you would want to know. It can also read all fault codes and carry out a reset. Most importantly it can read the MAFS!!

You can connect the software either via a bluetooth OBD-II port adaptor or buy GoPoints GL1 cable (US$99.00). The cable plugs your iPhone straight into the OBD-II port and powers the phone too so it charges the phone at the same time!

Cheers Bosshog.

You are a goldmine of good information.

Murph

Well I have now measured the fuel economy since the MAFS was replaced. Sure a little bit of country driving but I am back to 13.6l/100. Normal fuel 'economy' for me is 14.5 (remember I am running a hot tune with the chip)

There is no doubt that ute is running better and is clearly using less fuel. Could it be that the MAFS was not working correctly for sometime before it finally threw in the towel and therefore was affecting fuel economy?

BH

Old.Tony said:

This is a BRILLIANT product. Cost me $4.52 at the time. I've customised the gauges so this is what I get to see while driving:

Click to expand...

Hello

I have Navara D40 2008 and I decided to use DashCommander with ELM327.
Have you right Profile for D40 2008?

Thanks in advance

Welcome to the forum, Wandel.

I am not familiar with that product, I use Torque and you create a profile and edit it to suit the engine capacity, vehicle weight, fuel type etc - rather simple.

Many of the ECU's PIDs accessible by these programs are not capacity-dependent. Fuel rail pressure, boost pressure, coolant temp etc - they are just reported figures and don't require any calculation. Can you use a default profile and modify it for fuel type and engine size?

Old.Tony said:

Can you use a default profile and modify it for fuel type and engine size?

Click to expand...

Thanks for friedly response.
There is default profile but it is not complete. Could you say the profile for Torque?
I think it could be similar.

Sure can. On the left is the field name with a colon : after it, and to the right is the data. It's mostly pretty obvious stuff, but suited to my car (which is 2500kg empty).

Profile Name: Navara D40
Engine Displacement (litres): 2.488
Weight in kg: 2500.0
Fuel type: Diesel
Boost adjustment: 0.0
Max dial RPM: 5000
Volumetric Efficiency: 85.0
Fuel Cost: 1.5
MPG 'Trim'*: 1.9
Advanced features: disabled
Use Alternate OBD Header: disabled
Preferred OBD2 Protocol: Automatic - Thorough Search
-end-

* Not sure this is right, I'm still experimenting with this one

That's all of the options. I have to play with the efficiency and the trim figures, because the instant LPHK figures are way off what I would expect - on a highway cruise I'd expect to see around the 9-10LPHK but I'm getting 7s, and I don't think that's right.

Old.Tony said:

Sure can. On the left is the field name with a colon : after it, and to the right is the data. It's mostly pretty obvious stuff, but suited to my car (which is 2500kg empty).

Click to expand...

Thanks

I'm waiting new ELM327 and after that I will try.