I was having issues with the tps so I bought a new one. Got the new one in and I'm only able to get it to read a 0.50v on the output. What is up? It's a new tps and should be reading well into the 0.80v that are desired. I'm thinking it might be because of how cold it is? It's in the mid 30's right now. The grounds are all in tact and I have removed the braided ground strap for a larger gauged wire, I believe it is a 4 gauge wire. What could be the cause of this???

 

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I reattached the tps this afternoon and tinkered with it, but I could not get it to read over .5 volts. I have no clue why this is since it is a brand new tps. My old tps was the same way so clearly it isn't the actual sensors issue. Does anyone know where the ground wires lead, it could be possible that the ground is faulty or needs a bigger wire.
Also when I plug the engine side of tps in I get a high idle at around 2000 rpm. When I unplug the engine's side of the tps the idle drops down and the engine runs smoothly. I drove it around like this and it honestly seems less finicky with the engine side of the tps removed than having it plugged in.

Help me out here!!?!?

 

Got the tang of the TPS on the correct side of the linkage so it moves with the linkage?

Are you adjusting the tPS on the Engine side per this?


RENIX TPS ADJUSTMENT

Before attempting to adjust your TPS, there are two things that need to be done.

1) Be sure the throttle body has been recently cleaned. It's especially important that the edges of the throttle butterfly are free of any carbon build-up.

2) With the Key OFF, and using the positive (red) lead of your ohmmeter, set on the lowest scale, probe the B terminal of the flat 3 wire connector of the TPS. The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it parallels the valve cover and also over near the MAP sensor on the firewall. If you see more than 1 ohm of resistance, or fluctuation in your ohms reading, some modifications to the sensor ground harness will be necessary. The harness repair must be performed before proceeding. I can provide an instruction sheet for that if needed.

TPS ADJUSTMENT FOR ENGINE ISSUES

Both RENIX manual and automatic transmission equipped XJs and MJs have a flat three-wire connector to the TPS which provides data input to the ECU. The three wires in the connector are clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. DO NOT UNPLUG THE CONNECTORS !! Key ON, measure voltage from "A" positive to "B" ground by back-probing the connectors. Note the voltage reading--this is your REFERENCE voltage. Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts. Loosen both T-20 Torx screws attaching the TPS to the throttle body and rotate the TPS until you
have achieved your desired output voltage. Tighten the screws carefully while watching to see that your output voltage remains where it is supposed to be. If you can't achieve the correct output voltage, replace the TPS and start over.

Sometimes, after adjusting your TPS the way outlined above, you may experience a high idle upon starting. If that happens, shut the engine off and reconnect your probes to B and C. Start the engine and while watching your meter, turn the TPS clockwise until the idle drops to normal and then rotate it back counterclockwise to your desired output voltage.

TPS ADJUSTMENT FOR AUTOMATIC TRANSMISSION ISSUES

RENIX automatic transmission equipped XJs and MJs have a TPS with two connectors. There is a flat three-wire connector, same as the manual transmission vehicles have, and it is tested the same as outlined above—FOR ALL ENGINE MANAGEMENT RELATED ISSUES.

However, the automatic TPS also has a square four-wire connector, clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module. THIS SQUARE FOUR WIRE CONNECTOR IS USED FOR TRANSMISSION/SHIFTING RELATED ISSUES ONLY. First off, DO NOT UNPLUG THE CONNECTORS !! Key ON, measure voltage between "A" positive and "D" ground by back-probing the connector. Note the voltage. This is your REFERENCE voltage. Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved this percentage. If you can't, replace the TPS and start over. So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and the other side feeds the TCU.

For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced. The square 4 wire connector is just not used.
Revised 12-15-2013

 

Yes those are the exact instructions that I am following. I'm going to check the grounds per your guide and also do your sensor ground update and see if that changes anything.

 

Excellent idea.

Also, look at the tang of the TPS and see that it moves when the throttle linkage is actuated.

 

Okay its been awhile since I've been caught up with school, but I finally got around to redoing the the sensor ground crimp. But this didn't rid me of my issue. I am still only getting .51 volts on the output. What else could be a cause? Do I need to add a secondary ground to the tps?

 

Have you done Tip #1?

 

Yes, I rebuilt the motor two years ago and I made sure I scrapped all the paint off for the dipstick stud. I also added in 4 gauge cable from the head to the firewall and another from the negative battery post to the radiator support.

 

Sorry to bring a dead thread back up, but for the past couple of months I have just been driving with the engine side of the tps unplugged. Today I decided to poke around trying to find a fix to my low output voltage issue. I added a secondary ground on the engine side of the tps and this didn't solve the issue. I was poking around trying to find continuity between the TCU and the connectors and I found that A to D was found to be continuous with the ignition on. This is to say D1 and D3 are continuous when back probbing the TCU. So this leads me to believe I have a short somewhere inside my TCU correct?

 

Possibly. I've been troubleshooting an electric dryer tonight and all my electrons need a rest.

 

I think you would have shifting issues if that were the case.

What voltage issue are you having on the engine side. Input or output?

 

I have a low output voltage on both the engine and the tranny side of the tps. I'm getting something like .52v on the engine side and I don't remember the trannys side right off.
The transmission seems to shift fine and act normal despite this. When it is in comfort mode it shifts earlier and locks in to od when cruising. When in power it will hold the gear longer before shifting. The only symptom I have is a high idle when the engine side of the tps is connected. When I disconnect the engine side the idle returns to its normal speed.
I'm thinking maybe my voltmeter is off. Except testing it on the battery I do get 12v like it should be. I'm thinking of buying a mechanical meter to douple check the output.

 

What's the input voltage at either side?

 

Just below 5v on both sides

 

Like 4.8 or 4.9?

That's perfectly fine. Only thing that can affect the output voltage is the tPS itself then.