Renix Throttle Position Sensor (TPS) testing / adjustment

[BLHTAZ]

THROTTLE POSITION SENSOR (TPS)

 

1) Turn ignition on. Check throttle position sensor input

voltage. Connect voltmeter negative lead to terminal "B" (M/T), or

terminal "D" (A/T) of sensor connector. Connect voltmeter positive

lead to terminal "A" (M/T and A/T) of sensor connector.

 

NOTE:

• On (A/T) models, connector terminals are identified by
  letters molded into back of connector. On all models, do not
  disconnect TPS harness connector. Insert voltmeter test
  leads through back of wire harness connector. On some
  models, it may be necessary to remove throttle body from
  intake manifold to gain access to sensor wire harness.

 

2) Move and close throttle plate completely (M/T and A/T).

Ensure throttle linkage contacts stop. Note voltmeter reading. Input

voltage at terminals "B" and "A" (M/T), or terminals "A" and "D"

(A/T) should be 5 volts.

 

3) Return throttle plate to closed throttle position (M/T

and A/T). Check sensor output voltage. To do so, disconnect voltmeter

positive lead from terminal "A" and connect it to terminal "C" (M/T),

or terminal "B" (A/T).

 

4) Maintain throttle plate in closed position (M/T and A/T).

Ensure throttle linkage contacts stop. Note voltmeter reading. Output

voltage should be .8 volt (M/T), or 4.2 volts (A/T).

 

5) If output voltage is incorrect, loosen bottom sensor

retaining screw and pivot sensor in adjustment slot for a coarse

adjustment. Loosen top sensor retaining screw for fine adjustments.

Tighten screws after adjustment.

[ifixit8]

Nice write-up, wish I would have had that when I had my 99 cherokee. I thought for sure that was one of the possible colprits to it not running right. or that it might have had a blown trans. oh well that cherokee has been gone for a couple of years now.

[BLHTAZ]

I forgot to note it, but I just copied it from the FSM...I didn't write it... :oops:

[mjdoa]

Either way,thanks for going to the trouble.

[Darren]

I am totally doing this today.

[88XJSport]

Nice write-up, wish I would have had that when I had my 99 cherokee. I thought for sure that was one of the possible colprits to it not running right. or that it might have had a blown trans. oh well that cherokee has been gone for a couple of years now.

 

87-90 Cherokee/Comanche's had adjustable TPS only. Anything over 91 don't need adjusting.

[88XJSport]

So is it a bad thing if the Input voltage is 4.66 instead of 5.0? I adjusted the output voltage to 3.87, to get the required .83, but I was just wondering if less than 5.0 is ok...

[tallon2064]

Already did it, makes a world of difference. :clapping: :thumbsup:

[Shandley]

Does this count for the 2.5L manual transmission as well?

[ajpolitz]

So is it a bad thing if the Input voltage is 4.66 instead of 5.0? I adjusted the output voltage to 3.87, to get the required .83, but I was just wondering if less than 5.0 is ok...

 

Just decided to adjust my TPS and ran into the same issue.

A-D 4.67v closed

A-B now .81v closed and 4.67v open throttle.

 

'89 Jeep Comanche Eliminator 4.0l A/T.

 

Anthony

[ajpolitz]

I found this spec on another Jeep site, this one is the way my system reacts when trying to adjust the TPS.

 

This might work for you on the TPS:

 

THROTTLE POSITION SENSOR (TPS)

1) Turn ignition on. Check throttle position sensor input

voltage. Connect voltmeter negative lead to terminal "B" (M/T), or

terminal "D" (A/T) of sensor connector. Connect voltmeter positive

lead to terminal "C" (M/T), or terminal "A" (A/T) of sensor connector.

NOTE: On (A/T) models, connector terminals are identified by

letters molded into back of connector. On all models, do not

disconnect TPS harness connector. Insert voltmeter test

leads through back of wire harness connector. On some

models, it may be necessary to remove throttle body from

intake manifold to gain access to sensor wire harness.

2) Move and hold throttle plate at wide open throttle

position (M/T), or close throttle plate completely (A/T). Ensure

throttle linkage contacts stop. Note voltmeter reading. Input voltage

at terminals "B" and "C" (M/T), or terminals "A" and "D" (A/T) should

be 5 volts.

3) Return throttle plate to closed throttle position (M/T),

or maintain throttle plate in closed position (A/T). Check sensor

output voltage. To do so, disconnect voltmeter positive lead from

terminal "C" and connect it to terminal "A" (top) of sensor (M/T), or

from terminal "A" and connect it to terminal "B" (A/T).

4) Move and hold throttle plate in wide open throttle

position (M/T), or maintain throttle plate in closed position (A/T).

Ensure throttle linkage contacts stop. Note voltmeter reading. Output

voltage should be 4.6-4.7 volts (M/T), or .2 volt (A/T).

5) If output voltage is incorrect, loosen bottom sensor

retaining screw and pivot sensor in adjustment slot for a coarse

adjustment. Loosen top sensor retaining screw for fine adjustments.

 

Hope it helps.

[bluzmj]

I replace my TPS on 89 4.0 comanche, my problme is that I only get @ 2.07 volts on the input and 2.86 on the output no matter where I adjust it.

any clue of what I'm doing wrong.

[cruiser54]

 

 

CRUISER'S MOSTLY RENIX TIPS

RENIX TPS ADJUSTMENT

OCTOBER 30, 2015 SALAD 93 COMMENTS EDIT

 

Before attempting to adjust your TPS, there are a few 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.
3. 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. It is covered in detail in Tip 6.

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!

1. KEY ON, measure voltage from “A” positive to “B” ground by back-probing the connectors. Note the voltage reading–this is your REFERENCE voltage.
2. KEY ON, back-probe the connector at wires “B” and “C”. Measure the voltage. This is your OUTPUT voltage.
3. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts.
4. 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.
5. 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!

1. KEY ON, measure voltage between “A” positive and “D” ground by back-probing the connector. Note the voltage. This is your REFERENCE voltage.
2. Back-probe the connector at wires “B” and “D”. Measure the voltage. This is your OUTPUT voltage.
3. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. For example 4.8 volts X .83=3.98 volts.
4. 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 7/08/17

 

[Hammloaderman]

Hate to revive an old thread... But I have the one year that none of the tips on this page seem to match, I have an 86 comanche 2.5 auto 4x4 that I've been having problems with and I believe I've narrowed it down to the tps, mine as I'm sure you know does not have 2 connectors, is there any other vehicles I could rob one off of to test and see if it is my tps that's causing me all this grief? Before I spend the 70 bucks to buy a new one

[Lance Day]

Got an 89 Comanche 4.0, tps input is 5.13. It should be 5.0 max input. So how could you get more than 5.0. Where does the input voltage come from. What does it mean

[Ωhm]

The ECU has what's known as a 5vdc Supply Circuit (Network) for varies engine control sensors. But I believe the ECU uses 5.12vdc voltage regulator to control this.

[Lance Day]

So I guess that's ok. Was thinking bout updating the ecu to a 91,they said it gives 10 HP more. Any comments yes or no.

[Ωhm]

I know early years (87-88) ECUs are being replaced by later years ECUs (yes, more pep). Need a parts guy to check part numbers for 89 ECUs and 91 ECUs. May be the same.

[Ωhm]

Don't think 91 used RENIX ECUs.

[Pete M]

I think you're talking about the 1990 ECU upgrade. 

 

1991 would be a completely different animal.  

[cruiser54]

My website has info regarding upgraded ECU s for Renix.

[Lance Day]

TY guys 4 the info. Got the throttle body off cause the new  screws that came with the new tps came out with no threads. That first, I'll let u know

[WanderingAccountant]

Thanks to everyone, and to @cruiser54 for the detailed write up! I was able to adjust my TPS as directed, and it made a huge difference, but I noticed that my output reading jumps from the .828 that I set before startup to .843 after I cut the ignition. Subsequent start ups appear smooth and sound fine, but I am worried I did not tighten my TPS enough and it is turning out of position with each start up.

 

Is this normal?

[cruiser54]

Check it again in a week.

[WanderingAccountant]

@cruiser54 so I keep getting my TPS output reading on the nose accurate, but after 3-4 days of driving, the Comanche will either start in crazy high idle (the reason I started the journey of adjustment to begin with) or like yesterday, will struggle to start and requires pumping the gas to ignite. I am having to re-adjust every few days; this cannot be right!

 

I should mention that this is a new TPS that I just installed. Any ideas how to make the sensor stop moving around?