how to check tps on renix

Ok so I have a chilton's I want to check my tps.
Chilton says to unplug the connector at tps.
Which one there is two.

Then it says with key on check black and grey wires.
Is that the black and grey on female side or male side of connector.

Then it says engage connector and check the blue and black wires.

How do I check that if the connector is back on. Do I go through the connector where the wires enter.

There are two ways to go about it.

If your manual (Chilton's) sez to disconnect one plug, and you're seeing two, you've got the auto. The four-pole (2x2) plug is for the TCU, that's the one you unplug. The three-pole (1x3) is for the ECU - you want to leave that one hooked up.

The FSM sez to "backprobe" the plug. You can use a couple of straightened-out paperclips to do this. What you end up doing is slipping the paperclip wire in alongside the wire from the back of the plug, inside the seal, and reading the voltage while it's still connected. However, since the TCU side works in the opposite direction from the ECU side, you'd get different readings. I'd have to dig out a RENIX FSM to tell you what you should see - unless someone has one handier than I do (I'm in the middle of housecleaning.) I consider backprobing more reliable.

What are you checking for? If your idle speed is off, that probably comes from TPS misadjustment at idle/closed throttle. If you have difficulty accelerating, that could be a 'flat spot' on the TPS itself (it's a carbon strip variable resistor,) and that is best checked with an analogue voltmeter or ohmmeter. You're going to be checking the action of the change across the scale, and that's not normally doable with a DMM (due to the internal buffer circuits they're all built with.) Good news - with an ohmmeter, you don't need the engine running. Unplug the connector, probe into the TPS side, and work the throttle slowly and smoothly. If you see any "skips" or "hangs," you have a flat spot and need to replace the sensor (I had that trouble with my 88 - ran like a turtle 2200-3200rpm. Fine everywhere else. Checked and replaced the TPS, and it ran like a raped ape afterwards.)

You want the 4-wire connector.

Check A to D should be 5.0 volts.

If ok, reconnect and then check b to d with key in RUN position, throttle closed, should be 4.15 volts.

You can use a couple of sewing needles as probes to get through the Weather Guard connector.

joe_peters said:

You want the 4-wire connector.

Check A to D should be 5.0 volts.

If ok, reconnect and then check b to d with key in RUN position, throttle closed, should be 4.15 volts.

You can use a couple of sewing needles as probes to get through the Weather Guard connector.

Click to expand...

If you do that, I'd like to suggest a couple of things...

1) Use straight pins instead of sewing needles - the little heads on them are a huge help. The coloured plastic heads are even better.
2) Before you use them, round off the points on a stone so you don't puncture the seal. You want to slip in alongside the wire, not make a new hole.

Both good points.

I ended up buying a pair of Fluke backprobes.

Ok thanks for the help. I will check soon.
I am checking tps because trans won't shift correctly unless I floor it

If i Iam just driving around town the engine doesnt doesn'twant to shift until i Ifloor it.
Driving on the freeway is no issue since i Iam in 4th gear most the time.Ok eithier my tps is totally shot or I am testing wrong.

Ok on my 2x2 connector I have 3 wires.
I checked the volatge of each possible way.
Checked it pluged checked it un plugged.
Checked it with throttle wot and closed.

I never got more the 77 mv.
I am measureing in vdc.

The reason I am checking tps is my xj won't shift correctly.
Now if I floor it the trans will shift fast and smooth.

If the ecm sends a 5v signal to the TPS through the 3prong connector can I disconnect that and test to see if the 5v is getting to the tps.

jeepnleo said:

If the ecm sends a 5v signal to the TPS through the 3prong connector can I disconnect that and test to see if the 5v is getting to the tps.

Click to expand...

Yes.

Bear in mind it's a "nominal" 5VDC. It comes from a monitored reference circuit in the ECU - which is why you adjust the TPS to a value relative to the given reference voltage rather than to an absolute voltage level. If the reference voltage should wander slightly (perfectly normal,) the ECU can and do account for this in its readings.

Ok so I noticed today that two wires had melted insulation. So I replaced anyways. Took car for a drive and it ran great. The trans shifted fine.

So I figured ok I should see what the voltage is on the new one. But it didn't have correct measurement so I figure I just don't know how to check the tps.

If the xj runs fine do I need to make sure voltage is within spec.

No, because if it wasn't it wouldn't be running fine.