TPS Voltage

Nistune topics specific to the 6802 cpu

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vanepico
Posts: 21
Joined: Mon Jul 03, 2017 3:19 am

TPS Voltage

Postby vanepico » Mon Jul 10, 2017 8:06 am

Hi guys,

I've got my type 1 nistune board mounted into my ex auto ECU (Looks identical to the internals of the manual ECU I have). Everywhere all the way up to the ECU connector the TPS shows 0.3v (TPS position is definitely correct).

The signal will always be correct with the engine off, but sometimes when the engine is switched on, the TPS signal shoots up to 1-1.2v and fluctuates.

I would quite like to fix the ecu if at all possible, but for now I will switch the board over to the other ecu.

Has anyone else seen anything else like this before?

Cheers,
Pete

vanepico
Posts: 21
Joined: Mon Jul 03, 2017 3:19 am

Re: TPS Voltage

Postby vanepico » Mon Jul 10, 2017 11:25 pm


Matt
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Re: TPS Voltage

Postby Matt » Tue Jul 11, 2017 11:48 am

No I haven't seen that before

Have you measured the TPS signal input to the ECU? Your video description says 0.3V-0.4V?

Is this from multimeter against TPS signal ground and the TPS signal input?

Was it the same for both ECUs?

Nistune just reads the output of the AD converter and displays what it sees from the TPS signal

vanepico
Posts: 21
Joined: Mon Jul 03, 2017 3:19 am

Re: TPS Voltage

Postby vanepico » Wed Jul 12, 2017 7:53 am

Yes, the 0.3 - 0.4v was measured between ECU pin 38 and pin 30. I am pretty sure this is the same when the nistune is showing the tps at 1v.

I have noticed sometimes the 5v supply outputs 6.1v, whether this can be causing any problems?

It is strange how the manual says it should be 0.45-0.5, whereas mine says 0.3.

I was wondering whether maybe the nistune board/ECU ADC board may actually reference and earth signal, instead of the TPS ground, and if one of these earths may be damaged. You probably know more about the ECU layouts than me.

Yes it was the same for both ECUS.

I presume the 4 pin connector next to the EPROM is a serial connection for the diagnostics and sensor data?

Cheers

Matt
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Re: TPS Voltage

Postby Matt » Wed Jul 12, 2017 10:10 pm

4 pin connector is for other data lines (in addition to the ones to the socket)

6V output is not good. Your regulator might have a problem (hopefully not more than 5V to the Nistune board otherwise it will exceed limits of the chips on the board)

Perhaps try another ECU. Otherwise send the ECU and board here and I can test on the bench

vanepico
Posts: 21
Joined: Mon Jul 03, 2017 3:19 am

Re: TPS Voltage

Postby vanepico » Thu Jul 13, 2017 4:02 am

Is the 5v regulator built into the ECU do you know?

The TPS 1v problem was apparent in both ECUs I tried the nistune board, however I have only checked the supply voltage and signal directly with the multimeter one the first one.

vanepico
Posts: 21
Joined: Mon Jul 03, 2017 3:19 am

Re: TPS Voltage

Postby vanepico » Thu Jul 13, 2017 4:11 am

This is the closest I have found so far, so I will check my earths.

http://sxoc.com/vbb/showthread.php?4842 ... 13-ca18det)

vanepico
Posts: 21
Joined: Mon Jul 03, 2017 3:19 am

Re: TPS Voltage

Postby vanepico » Thu Jul 13, 2017 7:03 am

SOLVED!

I was instructed by someone that it was fine to run without the A frame on the side of the intake manifold. Little did I know, this carries the ground for the starter motor, and the alternator from the top of the intake manifold to the block. What I did, was I relocated the large earth strap down to where the A frame bracket bolts onto the engine mount, then using some 3mm core diameter wire I connected this up to the manifold.

I also have not put the choke back on my alternator which may have been causing more interference down the earth.

Thank you for your time Matt!

Matt
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Re: TPS Voltage

Postby Matt » Fri Jul 14, 2017 1:46 pm

Ah good stuff. I would have never guessed that not having seen the vehicle!

To answer your question - 5V regulator is a 3 pin part screwed to side of the ECU. Converts 12V to 5V and used to supply power to TPS and other 5V parts in the ECU

Normally starter and alternator grounds are to bottom of engine block and ECCS grounds top of plenum. The engine is the central grounding point of the vehicle, and all grounds run to it


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