Having trouble backprobing...help
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Joined: May 2002
Posts: 9,332
Having trouble backprobing...help
Trying to set my TPS to the correct voltage after installing a Pathfinder throttle body. I am not good with voltmeters in the first place. I have tried using the instructions in chapter 12 of my Haynes but it's not working for me. I put two straight pins in the rear of the TPS, white and back wires. I am getting no reading......I may not even be using the correct setting on my voltmeter either. Maybe I do not have the straight pins touching the back of the connector? But how am I supposed to know they are in the right place. Basically I am lost and have it a point on this project where I don't know what to do.
When I've backprobed in the past, I found I needed to hold he multimeter probes to the needle to get a consistent reading. That might be a little difficult for you if you are trying to adjust something while testing at the same time. As long as you are on volts you should be fine (Think the TPS is 0-5 volts or something). I always check my meter across the battery before testing just to be sure everything is working correctly with the meter too. You could try moving the pins around a little I guess if you still aren't getting a reading. Obviously too make sure you have the correct wires and the car is in the proper state for testing. Don't know if I was any help, but just my $.02 from experience.
Thread Starter
Joined: May 2002
Posts: 9,332
Originally Posted by MAXimumHP
When I've backprobed in the past, I found I needed to hold he multimeter probes to the needle to get a consistent reading. That might be a little difficult for you if you are trying to adjust something while testing at the same time. As long as you are on volts you should be fine (Think the TPS is 0-5 volts or something). I always check my meter across the battery before testing just to be sure everything is working correctly with the meter too. You could try moving the pins around a little I guess if you still aren't getting a reading. Obviously too make sure you have the correct wires and the car is in the proper state for testing. Don't know if I was any help, but just my $.02 from experience.
I need to get .4-.5 volts with the throttle closed....there is only one setting that gives me a x.xx reading and that is the ACA setting. I think I should be using the DCV setting, which gives me 12v at the battery. But the DCV setting on the voltmeter does not read decimals....which is what I need. Maybe that is my problem.
That does sound like it could be the problem. It's like trying to weigh yourself on a truck scale. Is there way to switch to millivolts (usually shown as "mV")on your multimeter?
Thread Starter
Joined: May 2002
Posts: 9,332
Originally Posted by MAXimumHP
That does sound like it could be the problem. It's like trying to weigh yourself on a truck scale. Is there way to switch to millivolts (usually shown as "mV")on your multimeter?
Nope, only one DCV setting and it won't give me a x.xx reading. Damn, I guess I need to go get a voltmeter that has more settings. I got this voltmeter as a gift...what does a good digital one cost?
So you need to read from 0 to .5 volts, is that correct?
So under your VDC you don't have different selections like 200mV, 2, 20, 200 etc.?
I'm thinking you can pick one up to do that for 20-30 bucks, 40 at most.
So under your VDC you don't have different selections like 200mV, 2, 20, 200 etc.?
I'm thinking you can pick one up to do that for 20-30 bucks, 40 at most.
Thread Starter
Joined: May 2002
Posts: 9,332
Originally Posted by MAXimumHP
So you need to read from 0 to .5 volts, is that correct?
So under your VDC you don't have different selections like 200mV, 2, 20, 200 etc.?
I'm thinking you can pick one up to do that for 20-30 bucks, 40 at most.
So under your VDC you don't have different selections like 200mV, 2, 20, 200 etc.?
I'm thinking you can pick one up to do that for 20-30 bucks, 40 at most.
Nope, DCV just has a single 1000 setting.
Guess I need to slap my brother for getting me a crappy mulitmeter.
So, I want to get a voltmeter that reads a minimum of 200mV right? Which will be able to read x.xx volts?
Thread Starter
Joined: May 2002
Posts: 9,332
Originally Posted by I30tMikeD
Guess I need to slap my brother for getting me a crappy mulitmeter.

Originally Posted by I30tMikeD
Well, I don't know the upper limit I need to test, just the lower limit whichis .5 volts.
So, I want to get a voltmeter that reads a minimum of 200mV right? Which will be able to read x.xx volts?
So, I want to get a voltmeter that reads a minimum of 200mV right? Which will be able to read x.xx volts?
Be sure too that when testing you don't overload the meter when testing the other limit (if you even need to). Each level can only read so high before they may blow an internal fuse (replaceable). So for example if the other limit is 12V, you should turn the meter to "20", so it would read out in XX.X
Thread Starter
Joined: May 2002
Posts: 9,332
Originally Posted by MAXimumHP

Yeah, as long as it can read in mV your good. I'm not really a meter expert either, but if the meter reads in mV, you can read .5 V. I think if it's set to "2", normally they read X.XX Volts, not positive though.
Be sure too that when testing you don't overload the meter when testing the other limit (if you even need to). Each level can only read so high before they may blow an internal fuse (replaceable). So for example if the other limit is 12V, you should turn the meter to "20", so it would read out in XX.X
Thanks for your help!
Thread Starter
Joined: May 2002
Posts: 9,332
Ok, got a new voltmeter. I can get a the TPS set to 450 on the 2000m setting, which should be .45 volts correct? I could not seem to get a good reading on the 200m setting. I could get up to 200 (.2)but then a small adjustment made it jump to 900 (.9).
So is the 2000m setting OK to use?
So is the 2000m setting OK to use?
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