Cel code 17, 21..

[Kane Rübernz]

Hey guys,

Newish to this forum (used to have an account about 7 years ago lol)

I have a EUDM DX (d13b2 Carb) that I have converted to a d16z6, obd1
Dash loom is a jdm obd1 auto loom with the auto section looped etc
p28 ecu with RP17/18 re-soldered etc
walbro external pump

Vss cel code popped up, had NO power on the yel/white wire, swapped the vss, checked the fuel tank wiring, noticed the clutch plug was not plugged in, plugged it, had power..

Drove it.. got to the realm of vtec.. speedo sh*t itself, then no speedo, and a nice code 21.

My guess is a bad earth, but I would like to know what else that could be?

So to summarize;
No vtec
No/intermittent speedo/odo


TIA

[Kane Rübernz]

Multimeter read power on both ends of the pressure switch? Lol

Guess I can just ground it to the thermostat as nothing is even on it.

[Kane Rübernz]

Ok.. so I cut the black wire (Vtec pressure switch) and earthed it on to the thermo.. Still no speedo or anything?

Multimeter on the VSS, 12v, 5v, ground.

Fuel gauge wiring is all good also.

Temp gauge seems to be reading V low or not even working?

------------------------------------------------------------------------------------------

Pre cutting the wire, the speedo would intermittently come on when in Vtec, although Vtec was not working?


Bizzare.

Someone please help!

[Kane Rübernz]

Bump

[teal_dx]

If you shut the car off, then back on, does the speedo work properly again, or is it always malfunctioning now?
Is it the original VSS? Mow many miles/km? Might be time to replace, as they go bad eventually. I see you did some wiring... possible short somewhere? I'd rather try& replace the VSS first, than chase a short in custom wiring.

[Kane Rübernz]

Hey,

It's got a new vss and the speedometer would kick in after VTEC (but not get VTEC and then get a cel code), so I checked the pressure switch, cut the earth and earthed it to the body.
No VTEC code now, but no speedo at all lol.

I reconnected the cut wire to the new body earth and yet, still nothing.

I will double check the vss wires but I'm sure they are getting power.. so it may be the earth for the vss

[Kane Rübernz]

All fixed now!

VSS was dead, plug to the VSS was also fried, and the Vtec had been bridged on the ecu at A4/D6.

Replaced the VSS and wire, unpinned the vtec at ecu and now it all works great!

[teal_dx]

Excellent! Not the first case of faulty VSS wiring I have seen. As these cars get older, it seems to be more of an issue.