Vn v8 auto, error code 42

Holden/Delco Tuning. ALDL, OBD 1.5. Circa 1989 to 2004.
Pezza
Posts: 3
Joined: Sat Feb 26, 2011 8:00 am
cars: Vn, vx and vy commodores

Vn v8 auto, error code 42

Post by Pezza »

Hi guys,

My car and a friend's, both have this code and we are going mad trying to work out the possible cause.

I did the tests that the gregories manual said, and it ended up saying replace the ecu or the ignition module. I've re placed the ignition module and both fuel pumps but its still running rough and stalling. Sometimes I dont even get code 42 but the engine light flashes as it coughs and splutters.

Basically I would like to know if any of you gurus think that its just the ecu, or it could be something else..

I'm tired of pouring money into it and having it still run bad...

Any ideas are greatly appreciated.

Thanks in advance :)
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muttley383
Posts: 83
Joined: Mon Aug 24, 2009 12:21 am
cars: VR 383 stroker

Re: Vn v8 auto, error code 42

Post by muttley383 »

EST 42 is a EST circuit fault on a VN I think.
I dont have the original manual for the VN but attached is fault finding process for a VR with EST Circuit Fault. On a VR this is DTC 41.
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Holden202T
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Location: Tenambit, NSW

Re: Vn v8 auto, error code 42

Post by Holden202T »

well the code info i have is:

42 Open or short on EST or BYPASS line to ignition module

this would make me look at the wiring going to the DFI make sure theres no issues with the 4 wires between the dfi and the ecm .... also check the wiring from the dfi to the cas!

are these cars v8's or v6's ?
vn5000
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cars: vn v8 commodore
Location: GOLD COAST QLD

Re: Vn v8 auto, error code 42

Post by vn5000 »

If its not the wiring thenits prob the ecm.
Ive had the ecu throw this code and the ecu is cactus about 3 times.
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Doctor Bob
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cars: VN, VT
Location: Melbourne Vic.

Re: Vn v8 auto, error code 42

Post by Doctor Bob »

yeah its a pretty common failure mode for the 808
Rob
Pezza
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Joined: Sat Feb 26, 2011 8:00 am
cars: Vn, vx and vy commodores

Re: Vn v8 auto, error code 42

Post by Pezza »

Thanks heaps guys,

muttley383: yeah, that's the tests i did, it got to the step saying "replace ecu"

I always thought you were never supposed to disconnect the ecu with the battery connected, but all those tests get you to do stuff with the ignition on etc..

Ordered an ecu off ebay, I'll let you know if it fixes it.

Thanks again! :)
Pezza
Posts: 3
Joined: Sat Feb 26, 2011 8:00 am
cars: Vn, vx and vy commodores

Re: Vn v8 auto, error code 42

Post by Pezza »

Thanks a million guys, new computer fixed it :)
bilsy
Posts: 9
Joined: Tue Mar 08, 2011 3:34 am
cars: VP Bench Seat Column Shift Wagon
VN SS 5 Litre 230HP atw

Re: Vn v8 auto, error code 42

Post by bilsy »

Hey guys im getting the code 42 read out also but mine dies only when it runs hot. wait for it to cool down and shes purring like brand new. Anyway i ran it through winaldl and these are the results i got hopefully you can help me.
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UCMatt
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2023 Audi S5
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Re: Vn v8 auto, error code 42

Post by UCMatt »

Wrong ECU selected in WinALDL.
The data reported is not useful until this is corrected.

From the description, sounds like a dead ECU or ignition module.
bilsy
Posts: 9
Joined: Tue Mar 08, 2011 3:34 am
cars: VP Bench Seat Column Shift Wagon
VN SS 5 Litre 230HP atw

Re: Vn v8 auto, error code 42

Post by bilsy »

hey matt which is the right one?

and i know its not ignition module ive test driven 3 all have same problem