Check Engine Light

[adam10_1990]

Ok so just bought myself another Commodore, this time a VT.


Every now and then i will get the check engine light, but i cant seem to find any issues.

Also it seems the my fuel needle (and the readout in diag mode) is incorrect, was on 16l, put in 20 l more and it jumped upto 55L.

The fuel also seems to decrease pretty quickly (was in diag mode down the highway) and its saying im only using 8l per hour and the fuel level dropped 15l in 30 mins.
When i got off the highway the level went up 5L and sat there.

I dont have a heavy foot, could there be a leak somewhere, where does the ecu get the reading for l/h from.

 

[monkey]

Im not real good on the electronic side of things but have you checked for fault codes yet? How many km do you get out of a full tank? Do the L/100km calc and see how off the computer is then. They will never be spot on more of guide or a gimmick.

 

[adam10_1990]

Ill do the fuel check soon,

but here my errors,

24 Vehicle speed sensor (no signal)
29 EGR position sensor fault
35 Idle speed error (IAC valve unable to control idle speed)
44 RH oxygen sensor (lean signal)
64 LH oxygen sensor (lean signal)
76 Air/Fuel ratio (variation between left and right banks)

Ill reset and do another check tonight

 

[accentstencil]

Sounds like you might benefit from some new oxygen sensors at least and maybe clean the IAC valve and throttle body. I don't know about the first two faults.

 

[monkey]

Unless its just loose connections, what accentstencil said. I reckon those errors would cause both poor economy and the computer to not be able to calculate accurately.

 

[adam10_1990]

Hmm, I disconnected the battery and turned the lights on to drain the rest of the power to reset the codes.

And when i started the car this morning it seemed very hesitant taking off from idle, it slowly fixed it self though so ill see how it goes on the drive home,

Would this just be the ecu relearning its different settings?

 

[jgtoranalc]

I had this saved in a Notepad File on my Laptop. I found the Info on this forum and forgot what Thread it actually was from.

Procedure to Reset Error Codes and Idle - VT Commodore
1.) Warm up car till its above 80 C
2.) Turn off the ignition (do not remove key)
3.) Remove the 10A fuse under the hood (Fuse is named as Eng Cont. BCM)
4.) Turn ignition on, but do not crank engine. Wait a minute untill dash beeps.
5.) (Do not turn off ignition) put the fuse back in
6.) Start the engine for five minutes, Idle may struggle but that is in the Learning Process

Now I did this process, It does work

 

[adam10_1990]

Cool, ill give this a go and report back hahahaha

 

[jgtoranalc]

Did you recheck the Error Codes after Disconnecting the battery? (After reconnecting the Battery obviously lol)....because recently I did the same Battery Disconnect Method on my brother's VT and the Error Codes did not reset.... and that's how I came across the other procedure in my previous post. Many people on this Forum still told me that the Battery Disconnect Method always works for them but I was puzzled why it didn't work for me.

 

[adam10_1990]

No i didnt do that cause i was running late for work haha, i use the system drain option, disconnect battery then turn on something to drain the residual power like lights or something.