New battery & Alternator causing Trans. Failsafe Prog

[mcfee03]

I'm taking it to my Indy to do the diagnostics...

I just picked it up from Bmw (who did nothing apparently) and it now logs a fault I've not seen


Injector fault.

[mcfee03]

So the Indy did a diagnosis, including a smoke test, some "adapter" tests on the gear box (?), and they concluded it is the MAF.

Said they were only keen to replace with OEM, which is about $460AUD....

They are only keen to do OEM (not used)...

They were super nice, and said I'm free to fit it myself, and bring it back to them to do the calibration.

On eBay they range from $40-$700....

Is an OEM/new MAF super important??

[upallnight]

Originally Posted by mcfee03

So the Indy did a diagnosis, including a smoke test, some "adapter" tests on the gear box (?), and they concluded it is the MAF.

Said they were only keen to replace with OEM, which is about $460AUD....

They are only keen to do OEM (not used)...

They were super nice, and said I'm free to fit it myself, and bring it back to them to do the calibration.

On eBay they range from $40-$700....

Is an OEM/new MAF super important??

Better to go to a breaker yard and buy an OE Siemens MAF then any of that crap that is sold on eBay or Amazon. As for calibration after installation, there is nothing to calibrate. Did they tell you what the flow rate the MAF was reporting when at idle? It should be grams/second. If you have the app Torque you can view real time data and one pid that the X report on is the MAF flow rate.

[mcfee03]

Originally Posted by upallnight

Better to go to a breaker yard

As for calibration after installation, there is nothing to calibrate. Did they tell you what the flow rate the MAF was reporting when at idle?

It should be grams/second. If you have the app Torque you can view real time data and one pid that the X report on is the MAF flow rate.

I can ask them what the flow rate was at idle- but I assume as it was a trans failsafe- the MAF wouldn't be doing anything?

[upallnight]

Originally Posted by mcfee03

I can ask them what the flow rate was at idle- but I assume as it was a trans failsafe- the MAF wouldn't be doing anything?

The MAF is there to let the computer know how much air is passing through the engine. With the known amount of air passing through the engine, the computer can calculate how much gas to add to mixture. The 02 sensor is there to let the computer know if the mixture is correct.

It may or may not be the cause of your transfail error code.

[mcfee03]

Originally Posted by upallnight

It may or may not be the cause of your transfail error code.

Really? I would have thought, given the testing the indy has done, along with his experience, that I could be confident in the indy's diagnosis...

I will look for a MAF from a wrecker.

[mcfee03]

Originally Posted by sgrice

Mcfee03 - I don't mean to sound like a pest, but I want to make sure you know what is meant by saying to check/replace the ignition switch.

Is it still worth me getting the ignition switch?

I asked the indy to check it. He said no, because the MAF sensor he's saying is the cause.

[upallnight]

Originally Posted by mcfee03

Really? I would have thought, given the testing the indy has done, along with his experience, that I could be confident in the indy's diagnosis...

I will look for a MAF from a wrecker.

The MAF from a 3.0 BMW from a 3 series or 5 series car will also work, so don't limit your search to just X5. If the MAF doesn't say Siemens on it, take a pass.

[bcredliner]

Originally Posted by mcfee03

So the Indy did a diagnosis, including a smoke test, some "adapter" tests on the gear box (?), and they concluded it is the MAF.

Said they were only keen to replace with OEM, which is about $460AUD....

They are only keen to do OEM (not used)...

They were super nice, and said I'm free to fit it myself, and bring it back to them to do the calibration.

On eBay they range from $40-$700....

Is an OEM/new MAF super important??

IMO always buy a new OE or OEM MAF. The MAF is critical to calculation of air/fuel mix. Don't buy a new ignition switch. Wait to see if new MAF corrects your problems. As already mentioned there is no calibration needed when replacing the MAF but the calibration could be for some other reason noted from Diagnostics.

[andrewwynn]

Originally Posted by upallnight;

The MAF from a 3.0 BMW from a 3 series or 5 series car will also work, so don't limit your search to just X5. If the MAF doesn't say Siemens on it, take a pass.

That's helpful info (siemens)