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Speed sensor reads zero
Posted: 24 Mar 2013, 09:46
by kiwi300zx
On my 1990 300ZX TT auto, the speed sensor reads zero on road tests. However, the speedometer reads correctly to 1-2% againast a GPS calibration. The same speed sensor reading is obtained from Conzult-free so the problem is not with Datascan I. I'm using version 1.63beta but the result is the same as the vers 1.62. Any ideas?
Re: Speed sensor reads zero
Posted: 24 Mar 2013, 11:28
by Topdog781
Where do you get data scan 1.63?
Re: Speed sensor reads zero
Posted: 24 Mar 2013, 14:41
by kiwi300zx
On the "trip Computer" thread. Tom gives the link for the 1.63beta:
http://home.exetel.com.au/nds/NDSI/down ... 3Beta2.zip
Re: Speed sensor reads zero
Posted: 25 Mar 2013, 11:45
by Tom
So DataScan shows 0 but your speedometer shows speed within 1-2% of GPS?
If this is the case, check the speedo wire connected to the ECU. Maybe someone tried to overcome the speed cut
Re: Speed sensor reads zero
Posted: 07 Apr 2013, 09:20
by kiwi300zx
I haven't yet tried to trace the wires from the speed sensor but will do so. However, 2 days ago I bought a 1991 300ZX TT A/T in near mint condition. It also returns zero for the speed. The speedo is correct in both cases to 1% against GPS and that signal must come from the speed sensor. All other sensors read correctly. It seems unlikely that the 1991 300ZX has also had someone tinkering with the wiring so it looks more to me like NDS-I isn't reading the speed sensor from the ECU. Is that possible? Do other 300ZX models of these years (1990-91) read the speed sensor correctly via NDS-I? I'd really like to solve this because without the speed sensor, the trip analysis isn't a great help.