how do i test a tps

[92gsxbafaro]

i think my tps sensor is out it is a 3 pin sensor i can only find out how to test the 4 pin one. and would that sensor being out cause this to happen on the ecu? any help would be great thanks alot.

 

[Gstclipse69]

TPS Adjustment Bust out the multimeter

 

[rts91tsi]

Looks like your ECU still has the original Rubycon capacitors, and C108 has leaked some of its electrolyte. Time to get them replaced and the board cleaned up.

 

[92gsxbafaro]

Looks like your ECU still has the original Rubycon capacitors, and C108 is has leaked some of its electrolyte. Time to get them replaced and the board cleaned up.

i just bought that ecu and it was good before i tried to start it then that happened i already have a new one on the way but if i get a new tps do you think it will start?

nevermind i just tested the tps it seemed to be fine. i also looked at my coolant temp sensor i think it might be bad

 

[rts91tsi]

The TPS shouldn't have anything to do with your car not starting based off the fail-safe operations chart.

You really should get the service manuals and do some troubleshooting, and have that ECU repaired before the damage gets worse. As far as I can see, the ECU doesn't look to be in that bad of shape, other than what I already pointed out.

If you need a service manual...look here.

 

[92gsxbafaro]

is the tdc sensor the cas? because i have spark so wouldnt that mean that that is good? the only thing i cant figure out is why i dont have a fuel injector pulse could it be the coolant temp sensor causing this?

 

[rts91tsi]

After thumbing a few pages back in my manual, I noticed that if the TPS circuit is troubled that Engine Stop will occur. Sorry about that!

TDC sensor is integrated into the CAS, and with a bad ECT sensor your should still have an injector pulse.
However if the CAS circuit is troubled you will not have an injector pulse like the chart shows.

 

[92gsxbafaro]

After thumbing a few pages back in my manual, I noticed that if the TPS circuit is troubled that Engine Stop will occur. Sorry about that!

TDC sensor is integrated into the CAS, and with a bad ECT sensor your should still have an injector pulse.
However if the CAS circuit is troubled you will not have an injector pulse like the chart shows.

is there a way to check the cas on the car?

 

[rts91tsi]

Yeah, you can do some testing with it on the car.

Start by testing the harness to make sure you're getting power to the sensor from the ECU with the key on.

Pin 1 is located where the notch is on the connector, it should be about 5v.

Pin 2 should have the same voltage as pin 1.

Pin 3 should be battery voltage.

Pin 4 is the ground and should be checked for continuity.

If those test correctly than the sensor is probably bad.

 

[92gsxbafaro]

Yeah, you can do some testing with it on the car.

Start by testing the harness to make sure you're getting power to the sensor from the ECU with the key on.

Pin 1 is located where the notch is on the connector, it should be about 5v.

Pin 2 should have the same voltage as pin 1.

Pin 3 should be battery voltage.

Pin 4 is the ground and should be checked for continuity.

If those test correctly than the sensor is probably bad.

so the car can be bad while i still am getting spark?

 

[steve]

Yeah, you can do some testing with it on the car.

Start by testing the harness to make sure you're getting power to the sensor from the ECU with the key on.

Pin 1 is located where the notch is on the connector, it should be about 5v.

Pin 2 should have the same voltage as pin 1.

Pin 3 should be battery voltage.

Pin 4 is the ground and should be checked for continuity.

If those test correctly than the sensor is probably bad.

Keep in mind that the voltages on pin 1 and 2 depend on the position of the CAS.
The ECU provides the voltage via a pullup and the CAS either pulls it down or floats depending on the position of the trigger disk inside the CAS. The test is to make sure the signals switch the correct number of times are the CAS rotates. One does it four time per CAS rev and the other twice.

 

[rts91tsi]

OP, Since the CAS has the TDC (camshaft position sensor) and the crank angle sensor integrated into the same unit, one can be bad and the other good. Either way, if one is bad the unit has to be replaced.

If the TDC sensor is good you'll have spark, and if the crank angle sensor goes bad there will not be an injector pulse.

Don't take this the wrong way, but all of this info is in the manual. You really should obtain and read the info regarding the issues you're having, and then ask these type of questions if you still have uncertainties. I don't mind helping people out, but you have to try to help yourself first.

Steve, thank you for providing a more in depth explanation of how the CAS functions.

 

[92AWDHX40]

TPs issue no power to the connector tried several tps im sure one works, had some volts on link before now nothing.

 

[steve]

TPs issue no power to the connector tried several tps im sure one works, had some volts on link before now nothing.

OK, what's your question?

Are you sure that the ECU is powering up and providing the +5v sensor voltage to the TPS?
If so, I'd be checking that the voltage is present at the ECU, and then check the wiring between the ECU and TPS with my ohmmeter.

 

[92AWDHX40]

I had the volt on my log at .63 earlier now I have nothing on my log using link, I have voltage to the connector and at the ecu .455 volts on my volt meter.

 

[1990TSIAWDTALON]

Victor, whats going on with your ride??? Is it down now? That thing should have 5 volts going to it shouldn't it? Just seen your post so thought I'd give ya a shout. Marty

 

[92AWDHX40]

Fixed the tps issue all good now gonna drive it tonight, working on idle tuning now, with link. I had zeroed the tps out on link while tuning thats all.

 

[1990TSIAWDTALON]

Great man. I have to recalibrate mine tonite also as I am tuning this week and it all of a sudden started showing 6-7% on Link so I made sure it was ok for me to reset it and was told I could. I don't know why it was drifting tho, its solid on the TB. ??? Hmmm. GLad the car is going again tho!!!