omega v6 2.5i m reg

1.    31
2.     17
3.      73

can anyone tell me what the likely faults are

The codes are here

http://www.topbuzz.co.uk/info/fault_codes/fault_codes.htm

don't worry about 31, you always get that when then engine is not running

dragon33 wrote on 15. Jan 2007 at 18:35:

omega v6 2.5i m reg 1.    31 2.     17 3.      73 can anyone tell me what the likely faults are

IIRC, 17 is a knock sensor (won't stop it from starting, but may feel flat when going), 73 is the MAF, and the 31 is crank sensor (no rpm).

The 31 is non conclusive if can not running, as it means the ecu has not yet seen the rpm signal (so normal if car won't run, but may mean crank sensor fubar).

Never tried this, but should give a better idea; put the paerclip in, try cranking engine for 5 secs, then without turning ignition from II reread codes.  If 31 still there I would suspect crank sensor.

Crank sensor is the only v6 sensor that hasn't got a limp mode...

tunnie wrote on 15. Jan 2007 at 18:54:

don't worry about 31, you always get that when then engine is not running

Doesn't mean it ain't faulty...  ...I am worried about the 31 ;)

so what are the likely causes and how do i rectify them bearing in mind that eml is constantly on

dragon33 wrote on 15. Jan 2007 at 19:10:

so what are the likely causes and how do i rectify them bearing in mind that eml is constantly on

Try my earlier suggestion of cranking it, then rereading codes without turning ignition off...

tried cranking it for 5 secs same result.
code disappears when engine running just 31 and 73.

sorry 17 and 73

Sorry, I thought engine wouldn't start?

What was problem?

engine wouldnt start on saturday after i had cleaned spark plugs below idle control valve,after stripping loom in casing and checking for any open circuit connections the engine fired up on sunday morning and was ok today back and fore to work apart from misfiring mainly at low speeds or under load,what does the knock sensor and maf relate too as far as likely problems

dragon33 wrote on 15. Jan 2007 at 19:35:

engine wouldnt start on saturday after i had cleaned spark plugs below idle control valve,after stripping loom in casing and checking for any open circuit connections the engine fired up on sunday morning and was ok today back and fore to work apart from misfiring mainly at low speeds or under load,what does the knock sensor and maf relate too as far as likely problems

Right, it all becomes clear ;)

17 = Knock sensor 2 = passenger side.

The knock sensor plugs into loom in the plastic cable tray that sits above passenger side plugs). It then disappears down near dipstick tube.

Check for damage along its length (often damaged if it gets caught under cam cover), and that its plugged in...

The knock sensor, btw, advances ignition until 'knocking' occurs. If ECU detects sensor fault, it retards ignition, and it will run like a pig, esp above about 2k rpm unde rload...

excellent it is plugged in but i did notice some black tape around it,also the other fault maf.i have noticed like an exhaust blowing sound coming from engine bay,somebody on here said it could be egr valve,or manifold gaskets,would that cause the maf code.

dragon33 wrote on 15. Jan 2007 at 19:43:

excellent it is plugged in but i did notice some black tape around it,also the other fault maf.i have noticed like an exhaust blowing sound coming from engine bay,somebody on here said it could be egr valve,or manifold gaskets,would that cause the maf code.

Ignore MAF code until knock sensor fixed...  ...MAF often give spurious codes when other faults present.  However, a blowing exhaust can cause a MAF code....   ...but I would see what happens when knock sensor fixed...

Without wanting to start an Error Code 31 debate....

My car always gives a 31 when not running and it always disappears when running. I have replaced a crank sensor (which fixed a problem) but the error 31 has always behaved in the same way.

So, I would say ignore the 31.

thanks for that jason h ,but anyway to "the boy" found problem eml now gone off  finally ,see if you can shed any light on this ,knock sensor wire consits of an outer screen and an insulated single wire,outer screen was broken and possibly shorting on broken piece of insulated wire ,i have now connected outer screen back up by way of a temporary link,is the screen irrelevant or is it a return path for pulses to the ecu.also would short in knock sensor stop car from starting.

dragon33 wrote on 15. Jan 2007 at 20:43:

thanks for that jason h ,but anyway to "the boy" found problem eml now gone off  finally ,see if you can shed any light on this ,knock sensor wire consits of an outer screen and an insulated single wire,outer screen was broken and possibly shorting on broken piece of insulated wire ,i have now connected outer screen back up by way of a temporary link,is the screen irrelevant or is it a return path for pulses to the ecu.also would short in knock sensor stop car from starting.

Knock sensor would not stop car starting. It would make it perform badly though.

The wire is a coax type, and yes, the screen is part of the circuit...

JasonH wrote on 15. Jan 2007 at 20:06:

Without wanting to start an Error Code 31 debate.... My car always gives a 31 when not running and it always disappears when running. I have replaced a crank sensor (which fixed a problem) but the error 31 has always behaved in the same way. So, I would say ignore the 31.

WRT to crank sensor codes...

19 is conclusive - knacker sensor
31 is non conclusive on a non running engine (I thought Dragon33's car wouldn't start)

I agree!!! The 31 code is no help to man nor beast  ;)