Hi all.

 

I was looking for some advice on Engine fault codes.

 

The yellow engine warning light is on and I have the following codes:

 

16486 - Mass air flow (MAF) sensor, bank 1 - low input

Possible Cause:

Intake leak, air filter blocked, wiring short to earth, fuse, MAF sensor

 

17544 :: Long term fuel trim, idling, bank 1 - system too lean

Possible Cause:

Fuel pressure/pump, injector(s), intake/exhaust leak, AIR system, hose leak

 

17705 :: Turbocharger (TC)/throttle valve, hose connection - pressure loss 

Possible Cause:

Hose connection

 

16891 :: Idle speed control (ISC) system - rpm higher than expected

Possible Cause:

Throttle control unit
 

I'm wondering if 17705 is the root cause of all of these? If so where do I look?

 

Many thanks in advance.

Edited 31 August, 201312 yr by MLH

A bit of a google suggests 16486 might me a more likely root cause.

 

Is that a reasonable assumption? Should I be looking around the air intake? Perhaps checking the Air Filter?

 

The car does seem to idle a bit randomly, usually a bit slow, sometimes a bit too quick.

Sounds like a boost leak, or split pipe between the MAF and turbo. O

More questions.

 

Elsewhere it's suggested to disconnect the MAF and see what happens? Is that a good plan? Or does the 16486 error mean all information from the MAF is ignored already and therefore disconnecting will have no effect?

 

I've had a cursory look at all the pipes I can see. Nothing looks split - in fact they all look good.

 

Could this simply be a blocked air filter?

 

TIA!

Edited 31 August, 201312 yr by MLH

Sounds like a boost leak, or split pipe between the MAF and turbo. O

 

Thanks. I'll have a better look.

If you need any help, I'm only in Bognor and I'm a mechanic 

If you need any help, I'm only in Bognor and I'm a mechanic 

 

You still stuck with this mate? 

Check the y pipe at the rocker box for holes - system is seeing unmetered air somewhere and putting up system lean warnings. Split boost pipe is also a good call.

 

Also, when was the throttle body last cleaned?. I would clean down the codes, run the car and see which ones return, as you may not know how old some of those codes are.

 

Hope it helps

 

Phil.