View Full Version : C20xe fault?
Right guys as you know ive recently fitted my c20xe into my nova today i finished the wireing off that needed doing which included the managment light. Everything seemed ok on start up ecu light went out an didnt come back on etc so i though all was good but i noticed that when i took it down the road and accelerated a little it came on:confused: so i stopped an turned it off and restarted it up all ok again light goes out as normal it seems only when i acclerate hard ish that it comes on and seems down on power like a kind off misfire:( the only problem is that the diagnostic wires have been taped up into the loom an im just wondering if anyones had the same type of problem off the top off there head before i have to untape the loom and find the wires:confused: which would be a ballache. Also if i drive normal it dosent come on which i find odd.
Now i hve found out that afetr driving it the ecu light comes on at 3000rpm no matter how hard you drive it so im lost unless anyone else has any other ideas if i stay below that its fine and dosent light up.
So any help would be appreciated guys.
Damo.
Just amended post so if anyone has any ideas rep waiting for any good answers.
Sounds like limp mode, and you will unfortunately have to find the diag wires and read the codes off the ECu to find the issue.
EDIT will it let you rev above 3k?
Yea lee it will it goes right round like it should but will only do it the once. once it has gone round it sends the light up and its really holding back badly untill you cut the ignition an restart then its normal again :confused: i carnt understand it myself ill have to dig thew diagnostic wires out anyhow and have a looksey.
Just a quick one are the dignostic wires the brown/white brown/red ones and can i join them together to get the light to flash the codes?
white and brown and white and yellow on mine damen,but i think you just put my white brown to the chassis and it flashes the ecu light to reveal codes
white and brown and white and yellow on mine damen,but i think you just put my white brown to the chassis and it flashes the ecu light to reveal codes
Cheers mate all try it.
+rep.
Right flashed the codes and got the following.
code 13 which is oxygen sensor open circuit/low voltage.
code 16 knock sensor low voltage.
code 73 afm low voltage.
found these on top buzz does anyone have any suggestions as to why or are have they just had it?
Damo.
Southie
02-03-10, 02:54 PM
Seems like it could be a dodgy earth if your getting low voltage on them all. Also I had something similar on my c16xe but it was a dodgy VSS (vehicle speed sensor) on mine which was earthed badly.
General Baxter
02-03-10, 03:06 PM
have you wiped the codes since fitting the 02 sensor ?
have you wiped the codes since fitting the 02 sensor ?
Yea nick ecu were unplugged over night which should have wiped the codes yea?
Seems like it could be a dodgy earth if your getting low voltage on them all. Also I had something similar on my c16xe but it was a dodgy VSS (vehicle speed sensor) on mine which was earthed badly.
Yea i was thinking the same southie because i carnt see them all being no good :tard: would not having a gearbox earth on have anything to do with it do you reckon.
Southie
02-03-10, 04:32 PM
Yea i was thinking the same southie because i carnt see them all being no good :tard: would not having a gearbox earth on have anything to do with it do you reckon.
Worth a try, all of the Novas need plenty of earths.
Worth a try, all of the Novas need plenty of earths.
Yea were thinking that mate mine were an spi to start with so i never had one but mine had two earths from the battery one to bulkhead and one to starter so i thought it may not need one. :tard:
Install a g/box earth, and check the engine loom earths probably, I take it you screwed down the 3 main ones to the injection rail, and wired the earth on the loom to the chassis as well?
nova-taken
02-03-10, 04:59 PM
as said, sounds like an earthing problem, when we XE'd my mates corsa, we had a similar problem with underpowering and going into limp mode, but after we placed a good earth to the g/box, and injection rail
hope that helps you in some way
Install a g/box earth, and check the engine loom earths probably, I take it you screwed down the 3 main ones to the injection rail, and wired the earth on the loom to the chassis as well?
Yea done the ones on the rail lee 1 near the fpr an 2 near the coldstart valve:wtf: . Didnt know there were anymore on the loom though? Were is the other one then mate?
as said, sounds like an earthing problem, when we XE'd my mates corsa, we had a similar problem with underpowering and going into limp mode, but after we placed a good earth to the g/box, and injection rail
hope that helps you in some way
Yea cheers mate am pretty sure its an earthing problem too gonna retrace all my earths back an make sure of a good connection.
nova_saloon
02-03-10, 05:44 PM
if not but an extra earth on the block. mine wouldnt start ptobs untill i got an extra earth. but check the wiring to. might be a bit corroded
if not but an extra earth on the block. mine wouldnt start ptobs untill i got an extra earth. but check the wiring to. might be a bit corroded
Yea will do mate gonna try g/box earth an see what i get first like i said am pretty sure its an earthing problem.
Yea done the ones on the rail lee 1 near the fpr an 2 near the coldstart valve:wtf: . Didnt know there were anymore on the loom though? Were is the other one then mate?
The engine loom has a main earth which would have connected via the big multiplug OR straight to the battery depending on its age.
The engine loom has a main earth which would have connected via the big multiplug OR straight to the battery depending on its age.
Oh yes mate you mean on the mini loom from the battery? yea there connected mine was an spi to start with so ive 2 one goes to the bulkhead and the other to the starter bolt :thumb: .
Just realised that ive no earth strap on the alternator wouild this cause these symptoms?.
Right flashed the codes and got the following.
code 13 which is oxygen sensor open circuit/low voltage.
code 16 knock sensor low voltage.
code 73 afm low voltage.
found these on top buzz does anyone have any suggestions as to why or are have they just had it?
Damo.
causes major missfiring when booting it, fixed when ignition turned off. i think i got a spare one in my tool box, then again check the wires to make sure they havent been rubbin on something
causes major missfiring when booting it, fixed when ignition turned off. i think i got a spare one in my tool box, then again check the wires to make sure they havent been rubbin on something
It dosnt misfire bubba it just holds back really bad an seem to drive really rough with the management light on but like i said if i turn the ignition off an on again its ok till i reach 3500rpm again:confused: .
How much for the knock sensor if you have a spare just incase i need one?
L33 LEG
03-03-10, 10:42 AM
i might check my knock sensor then, could be the cause of my problems. i cant think where it is though...?
Southie
03-03-10, 11:31 AM
i might check my knock sensor then, could be the cause of my problems. i cant think where it is though...?
The knock sensor is on the rear of the cylinder block.
Also you have PM. :d
L33 LEG
03-03-10, 01:46 PM
Cheers, il get it looked at soon. Actually i have just remembered what it is now, i had to buy one last year as my engine didnt come with one lol il double check to see if i fitted it right Lol.
Will pm you back in a min.
Right earthes trhe gearbox out now and it runs smoother than it did but still has the ecu light illuminating at 3000rpm am gunna try the alternator earth today but no sure if this is gonna cure it though.:confused:
General Baxter
04-03-10, 07:53 AM
fit a small block. on carbs, lol
fit a small block. on carbs, lol
Nar big block mate all the way small blocks for girls lol.
Right earthes trhe gearbox out now and it runs smoother than it did but still has the ecu light illuminating at 3000rpm am gunna try the alternator earth today but no sure if this is gonna cure it though.:confused:
Lack of alternator earth strap would mean the batteries not charging, im surprised its not died yet, and also you're probably running off the battery which could cause the issues you're having.
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