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2010-2012 Range Rover Sport
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120 Posts
Discussion Starter #1
Hey guys, I need a favor.

When I look in GAP, my "Bank 1 MAF Voltage" is showing as a negative 30 V - this obviously makes no sense. Some additional info:

1. I can switch MAF's side to side and this doesn't change anything
2. The Bank 1 and Bank 2 "MAF grams per hour" figures are virtually symmetric so it appears that the ECU is reading the incoming airflow properly
3. There are no MAF codes being thrown

I don't know if all L320's have dual MAF's, so if your car has a single MAF then you won't be able to help me.

I have contacted the GAP folks and this was their response:

"The IIDTool provides the same live value LRmade available thus we have no control over how they show up on the IIDTool. If both reading in g/s are identical, theissue is elsewhere. Also, the ECU will always show a fault when this type ofissue is present. In other words, issue is elsewhere."

While I understand the logic of his response, I find it hard to believe that if the ECU is actually being presented with a Bank 1 MAF voltage of -30V that it wouldn't throw a code! I feel like there is a bug in the GAP software, but perhaps I'm wrong.

Could someone test this for me? If you have a dual MAF L320 could you compare Bank 1 and Bank 2 MAF voltage?
 

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2010-2012 Range Rover Sport
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120 Posts
Discussion Starter #2
Ok just got another email from GAP:

"It does not receive a -30, the ECU gives out this value. Ignore it, bug in the ECU."

This makes a bit more sense but is still disconcerting. It would give me much more peace of mind if someone else with a dual MAF vehicle could verify they see the same behavior!!!!!
 

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2010-2012 Range Rover Sport
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16 Posts
I have one but dont know how to determine if I have dual MAFs. 2012 sport supercharged. I just noticed we hae the same exact car
 

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2010-2012 Range Rover Sport
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120 Posts
Discussion Starter #4
I have one but dont know how to determine if I have dual MAFs. 2012 sport supercharged. I just noticed we hae the same exact car
Yep, you have dual MAF's for sure.

If you connect GAP and go to "Live Values" can you add Bank 1 MAF voltage and Bank 2 MAF voltage and let me know what you see?

They will be under the "PCM" section - if I remember correctly you will need to scroll down until you see "MAF Bank 1 voltage" and "MAF Bank 2" or something like that.

Thanks
 

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2010-2012 Range Rover Sport
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120 Posts
Discussion Starter #7
Bank 1 - -30.7
Bank 2 - 1.36
Beautiful, thank you sir! That's exactly what I see.

So it certainly does appear there is some kind of bug in the Land Rover ECU, oh well.

Again, thanks!
 

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2010-2012 Range Rover Sport
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Any time, out of curiosity what made you want to look at it? I honestly dont know what its for and since we both had the same work done on same car made me wonder what prompted it for you. We also have pretty much the same mileage mines at 77

Beautiful, thank you sir! That's exactly what I see.

So it certainly does appear there is some kind of bug in the Land Rover ECU, oh well.

Again, thanks!
 

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2010-2012 Range Rover Sport
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120 Posts
Discussion Starter #9
Any time, out of curiosity what made you want to look at it? I honestly dont know what its for and since we both had the same work done on same car made me wonder what prompted it for you. We also have pretty much the same mileage mines at 77
Because my idle is still not perfect. Even after I walnut blasted my valves and did the timing job. (I did it all myself)

Your MAF sensors read incoming airflow into the engine and in conjunction with oxygen sensors are probably the most important (and sensitive) sensors on the vehicle.

MAFs are notorious for causing all kinds of issues, especially idle issues (and even more especially if you have a vacuum leak).

That being said, these 5.0 supercharged Jag motors are known to have a rough idle, and as far as I can tell no one has figured it out.

How is your idle? Mine is much better after doing all this work, but it still as an oh-so-very-slight "miss" that I can feel. It's tiny, but it's there.

Could I impose upon you one more time? Can you check the actual airflow at idle? There are 3 values I would like you to check:
1. Airflow Bank 1 (I think it's under "airflow" under PCM - it will read grams/hour)
2. Airflow Bank 2 (" ")
3. MAF airflow (I think this one is under "MAF" section like voltage - it will read grams/second)
 

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2010-2012 Range Rover Sport
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Bank one is between 11800-12300
Bank 2 the same they fluctuate

Where do i find the MAF airflow?

Sorry took so long
 

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2010-2012 Range Rover Sport
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Discussion Starter #12
Bank one is between 11800-12300
Bank 2 the same they fluctuate

Where do i find the MAF airflow?

Sorry took so long
OK yeah that's about where I'm at as well. I forget exactly where the MAF airflow is at, but that's OK, the side to side grams/hour is what I really needed.

I appreciate it!
 
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