The supply will put out 5 volts. As to how much the meter reads is dependent on the quality of the ground. The ground circuit of the TPS and other sensors can be tested like this:


Cruiser’s Renix Sensor Ground Test

This sensor ground circuit affects the CTS, TPS, IAT, MAP, ECU and diagnostic connector grounds. It’s very important and not something to overlook in diagnosing your Renix Jeep as it is common for the harnesses to have poor crimps causing poor grounds. If any or all of the sensors do not have a good ground, the signal the ECU receives from these sensors is inaccurate.
Set your meter to measure Ohms. Be sure the key is in the OFF position. Using the positive (red) lead of your ohmmeter, 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 runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too.
You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well.
Revised 06/12/2012

 

messed around a bit today,to start,tested meter on battery,11.80Volts.ran seperate ground off the 3 prong with no change,2.60volts in.tested meter on braided ground strap hooked + to battery,tested good.tested ground at dipstick ground wires,tested good as well.
probed blue wire from the 3 prong after it comes out of the c101 same voltage 2.60,so not an issue in the c101 either.

also wiggled harness at ecu while someone observed meter readings,no change whatsoever.
wiggled harness at c101,had .2-3 fluctuation,the numbers when down,not up

 

fixed,was something in the c101,took it apart,cleaned it out,3rd time lucky.no more idle issue,still seems a little lean though.thanks a bunch for your input cruiser,a BIG help!!!

 

Did you "tweak" the receptacles as described in the write-up the first time?

PS: REALLY glad to hear you got it!!

 

cleaned 3 times with brake clean,elec contact cleaner,& potentially 1 plug was possibly pushed in a bit.I have 4.85 going in,and set tps to 0.82.no more miss,but still smells a little lean out the rearend................

 

So you never tweaked the receptacles so they grab the pins tighter?

Quit smelling rearends.

 

receptacles"tweaked"thats how I noticed the odd one.tks for the help cruiser

 

testing the map sensor,looking into why the Cherokee seems to be running lean,still idleing pretty good,I may have found the problem,checking volts,with key on,i am getting 0.00 volts at terminal B/purple wire output,& 5 volts at terminal A/input.wondering if this is the sign of a dead map,or output wire issue??

 

A is sensor ground. B is Map output to ECU, C is MAP supply voltage from the ECU.

Check the ohms on A with key off, Voltage at C should be about 5 volts key on, output at B varies with barometric pressure read from the manifold.

 

A.=.003ohms,my meter was set at 2k,
output b was 0.00 key on,& 1.75-1.88v running.
input c was 5v running,and 5v with key on.

I was thinking the voltage at b/output should be 5v as well,then drop when at temp/running..................

 

So, everything looks good as far as A and C. B, we need to know that a MAP should read at idle. What does B read if you stab the throttle open?

How are you determining that the exhaust "smells lean"?

 

exhaust burns the eyes,can smell it as well.

b goes over 4v when throttled up,4.15v

 

That's rich, not lean if it burns your eyes.

 

oh,plugs are white grey,as in running hot,running clean out the exhaust,no black smoke.................

 

Not rich then. What plugs? How old are cap, rotor and wires?