CEL (Code 14 & 21)

The car in question is a 91 Eclipse GST.... i know its not a VR4 technically, but you guys are very smart and helpful!! /ubbthreads/images/graemlins/worthy.gif

I was able to finally test the cable for the diag port, and it works. Found a palm IIIc sadly the battery is dead so i have to run an extension cord out to the car so the damn thing keeps power...if the power is lost, it loses everything.

Issue: CEL
Using the MMCD program, i was able to find out what codes were being thrown.
14 -Throttle position sensor
21 -Engine coolant temperature sensor

With MMCD running, and car off, the TPS was showing a 3.5% load. i would push in the pedal to the floor and the most it would do is a 96.5% load.
With me having multiple sensors around, i reset the ecu, waited 5mins, swapped in another TPS.... waited for Code to kick, once again it was TPS
The sensor was not connected to Throttle body and was showing a 0.0% load, with throttle to the floor, it would go to 99.6%.

Since the code 21 -which is caused by a split wire. (once i fix that with the connector that toybreaker sent, thx btw!) i hope to see that code disappear again.

Any ideas on why i cannot get rid of the 14 code? /ubbthreads/images/graemlins/banghead.gif It is possible that i have bad tps sensor(s). A new one runs 128$.
Also, i will use a circuit tester (light) to see if the line has a break in it.

-Thanks!

Rob /ubbthreads/images/graemlins/uhh.gif

 

[BoostedAWD91]

u might have a short in the circuit somewhere or the harness could be bad.

 

I hope thats what is causing the problem. Will find out tomorrow with the circuit tester.
Thanks for the quick reply

 

[Hertz]

Rob, have you tried adjusting the TPS to show 10% at idle (per the www.vfaq.com) ?

 

EDIT: Found it...

I will have to try that out! Thanks

 

You can adjust the TPS with your car on and the logger hooked up. Just move the TPS until it read 10%; then tighten it down and you should be good to go.

 

[chucklesas]

Quoting Kngnothg:
I remember at one time i found the answer there, but now i cant find it.

Would you kindly tell me exactly?

Thanks!



Look in DSM > Intake > Throttle Body
It's the last one under that heading.

 

Here are my results:

NOTE: CEL 21 is now fixed. /ubbthreads/images/graemlins/grin.gif

On the harness side, I got the 4.98V from pin 1.
On the sensor side, I got 5.04~K ohms between pin 1 and pin 4.
On the sensor side, I got .08K ohms between pin 2 and 4

Connected to pins 2 & 4 closed throttle is at .08k ohm and wide open is at 4.85 K ohm

By what is listed above as well as vfaq, the sensor is working ok.
Only thing left is to swap an ECU?!?! /ubbthreads/images/graemlins/dunno.gif

EDIT: Using a Matco MD118 (Heavy Duty Logic Probe)
Pin 1 glows Red
Pin 2 glows Green
Pin 4 glows Green

Red -shows voltage
Green -shows proper ground

 

[toybreaker]

Quote:
NOTE: CEL 21 is now fixed. /ubbthreads/images/graemlins/smile.gif



Sweet! /ubbthreads/images/graemlins/cool.gif

Quote:
Also, i will use a circuit tester (light) to see if the line has a break in it.



I'm always leary of using an old school test light on a 5 volt circuit. Depending on the age and quality of the unit, it can be easy to get into trouble.

The resistance of the incandessant bulb can be several orders of magnitude less than the circuit you are testing, and the test rig will pull considerably more current than the circuit was designed to supply. This can damage the 5 volt refernce power supply or a trace on the board before you know it. In addition, most traditional old school test lights are calibrated for 12 volts, so 5 volts may not even light the damn thing.

Quote:
EDIT: Using a Matco MD118 (Heavy Duty Logic Probe)
Pin 1 glows Red
Pin 2 glows Green
Pin 4 glows Green

Red -shows voltage
Green -shows proper ground



Now, that's a better choice for tooling, (as it's low current draw won't damage anything) /ubbthreads/images/graemlins/smile.gif

... but it's still not as accurate as an actual volt meter. It won't tell you how much voltage there is, only that there is "some".

[pitch:] As an aside, Snap on's power probe II has a voltmeter built into the unit, and is a much nicer piece, for anyone contemplating the purchase of a logic probe. You can actually supply power and ground to the circuit your testing with the power probe thru a rocker switch on the handpiece, and that is way cool! (note it supplies 12volts at the tip, so don't go zorching any 5volt circuits! It also has a guide light built into it that makes finding the connection you want to check under a dark dash much more precise.[/pitch]




Quote:
With MMCD running, and car off, the TPS was showing a 3.5% load. i would push in the pedal to the floor and the most it would do is a 96.5% load.



The low idle and wot numbers can come from a misadjusted closed idle switch and cable. The throttle linkage on the cars is very proggressive, and if you start low, many times you'll end up not reaching full travel at wot. One of the tells for a closed idle switch that has been tampered with is that to get the specified tps reading on a closed throttle, the tps ends up being near the end of it's adjustment travel. (twisted all the way one way or teh other) Another tell is where the biss screw ends up. All the way inny or outty indicates the base throttle opening is incorrect and you're having to add or subtract a sh*t ton of air thru the biss bypass to compensate. Follow the vfaq directions to the letter when you set up the biss, and verify there is a small iac count at all times when the engine is idling. Toss a little load at the system (turn the steering wheel, or turn on the lights), and verify the iac count increases, and you're good to go. When I'm trying to set a tps up, and it ends up out of the center of the range, I always start all the way over and set up base throttle opening before proceeding. It'll cut down on the tail chasing and ensure once it's set, it will stay set. A throttle plate that's too tight will stick in the goo of the throttle body bore every now and then and drive you nucking futs!

Quote:
By what is listed above as well as vfaq, the sensor is working ok.




Rob, it sounds like you did a damn good job following the vfaq, and something weird is going on.

Maybe Keydiver will have some ideas for you to try. /ubbthreads/images/graemlins/dunno.gif

Untill then, I would ohm out the ground with an actual ohmeter, and look very carefully at the various grounding points, especially the one on the firewall, and the one under the the ecu mounting hardware for corrosion or damaged wiring strands. From the connector end, they should read .2ohms or less to a known good ground.

Quote:
Only thing left is to swap an ECU?!?!



I have a known good ecu out here you can try, if you can't find one locally, just let me know.

It probably wouldn't be a bad idea to pull the ecu and check the board for corrosion. The acid residue from a hack and dash "repair" can continue to eat away at the traces long after the caps have been replaced, causing funky, one off problems like this.

Good luck, and please update the thread with the fix, so searchers can learn from your experience.

 

Your right! Something is going on weird here.

Check this out...

After i replaced the coolant temp sensor, the CEL light now goes on at idle, then when i push the gas it goes away.

I used the mmcd at idle, code 14 was active. I gave it some gas, the light goes away... code 14 is stored and NOTHING is active.

I logged a cold startup... did a couple WOT runs, wouldnt et to 96%TPS though... /ubbthreads/images/graemlins/dunno.gif

The idle will drop about 500, back up to 1000, 1300 and back down.. so im sure i need to redo the biss for sure.

Going to do that this afternoon.

 

[toybreaker]

Check the ecu board for damage before you go much further...

It almost sounds like you might be having trouble in the five volt reference area of life. /ubbthreads/images/graemlins/dunno.gif

 

[Brunoboy]

i say its the ECU, happened to me, and its currently happening again with my new ecu. Im having it recapped.
-shane

 

Quoting toybreaker:
Check the ecu board for damage before you go much further...

It almost sounds like you might be having trouble in the five volt reference area of life. /ubbthreads/images/graemlins/dunno.gif



I believe your right! The car does smell rich... as soon as i get a chance this weekend, its coming out.

 

[stevep]

If you all don't know this from me harping about it for years then I'll harp some more.

The VFAQ procedure for setting the TPS isn't correct for any DSM. You can't set the TPS accuratly by resistance unless you measure the total resistance, the actual sensor voltage and calculate the value for the voltage divider to give you an output voltage of between 0.48v and 0.52v

There is too much variance in the TPS specs to come up with a one size fits all value.

There are several conditions that will throw a TPS code and the output voltage being too low is one of them. If it's less than about 0.4v you will throw a 14 CEL. That may be the cause here.