Question about MAF wiring.

[cjsupra90]

I just noticed something that I should have asked before. Are you sure that your car had traction control? You said that you compaired it to another that had TRAC, but that doesn't mean that you had TRAC.

Did you buy this car not running or was it fine then all of a sudden a problem arose?

If your sure the car had TRAC and it was removed, and you bought the car not running, then I would start by looking at all TRAC connections as the previous owner eliminated as my guess is they tried to do something to eliminate any MIL that might appear due to the deletion of the TRAC system...

 

[thenewmexican]

I checked the MAF connector where the Blue/Red wire leads, both with the key on/off. It's always ground.
No 5V.


The resistance to ground on the Blue/Red wire with the ignition off is 124.2 OHMS.
The resistance to ground on the Blue/Red wire with the ignition on is -122.3 OHMS.

My measurements were made with the correct ECU in place 89661-50042

What else should I check for.

Thanks.

 

[sideshow]

stop checking things using resistance it will confuse u

u need to check everything using voltage

if the blue/red wire is ground u will have 1 ohms from wire to ground
this will fuk the ecu and burn out the 5 v output inside the ecu if the actual
wire was touching ground

just take it to an expert cause the way u r checking things is the wrong way
and the way yr explaining them is hard for us to understand

the blue/red wire has 5 v from the ecu thats all it does

if there is no 5 volts then its 3 problems

the ecu is wrong so pinouts are in different spot

or the ecu is fukt or the wire is cut

there is no other reasons

so sit down and figure out which one of these it is
otherwise take it to a pro

cause it will take months to fix it by asking on here if u dont know much
about wiring

 

[cjsupra90]

ok, you do have a short somewhere cause that resistance value is low. It should be at least 3000 ohms or so.... One the TPS, you'll have a VC pin and an E2 also just like the MAF. With the TPS unplugged, check the resistance between those two terminals and see what you get. It should be somewhere around 3000 to 4000 ohms. Should be the two end pins (pin 1 and pin 4) double check me by looking at the wires on the plug as they should be a blue /red and a brown.

I have a feeling that is has something to do with the removal of the TRAC system if that car did infact have it.....

 

[cjsupra90]

Sideshow, you do have a good point. Had we not been typing our replys at the same time and I had saw yours before hand, I probably would have agreed with you about just taking it to someone cause yeah he is explaining things in ways thats hard for us to understand

 

[thenewmexican]

Guys.
Please bear with me. I'll try to do a better job of explaining things.
Here is my situation. I live in a remote area of New Mexico. So remote,
that not even space aliens want to visit.

The nearest place I could find a professional to do the work is at least 50mi away.
So. I have no choice but to solve this problem myself.

I apologize for the bad wording for problem explanations. I will try to do better.

Thanks again.

 

[cjsupra90]

Ok, I'll try my best to help you out, but I cant promise anything...

First thing are you sure the car had TRAC? What makes you think that it had TRAC and was removed?

 

[sideshow]

its just hard figuring things out on here

and he doesnt want to strip loom back out of the car so he can sit it down and go over it

checking things with resistance is not the right way

basically if u turn ecu on and have 0v at throttle wire
u have wrong ecu or fukt ecu
if the wire did have 5 volts before u started and now 0v then u might have fried ecu

pull ecu out and smell it
check if there is still smoke inside cause if the smoke comes out its stuffed
i like adding that one heheheheh

maybe start from scratch and test what u can
get error codes from it
get correct diagram as there are 5 or so diff versions of 1uzs once u get past 94 95 and half the time ive had to sit down and work things out by testing wires and see what htey do with a scanner attatched

u will prob go round in circles if u dont pull some of it apart

 

[cjsupra90]

its just hard figuring things out on here

and he doesnt want to strip loom back out of the car so he can sit it down and go over it

basically if u turn ecu on and have 0v at throttle wire
u have wrong ecu or fukt ecu
if the wire did have 5 volts before u started and now 0v then u might have fried ecu

pull ecu out and smell it
check if there is still smoke inside cause if the smoke comes out its stuffed
i like adding that one heheheheh

maybe start from scratch and test what u can
get error codes from it
get correct diagram as there are 5 or so diff versions of 1uzs once u get past 94 95 and half the time ive had to sit down and work things out by testing wires and see what htey do with a scanner attatched

u will prob go round in circles if u dont pull some of it apart

This all I agree with,

checking things with resistance is not the right way

but this I disagree with..... If it wasn't right, service manuals wouldn't supply resistance values... These values in some circuits are very important... One example is I had a car that VC to E2 had 20ohms of resistance and that was close enough to a dead short and thus fried the 5v out put...

Outside of that, there isn't much that can be checked without pulling back some of the harness especially if it looks like it was damages in areas....

-----------------------------------

Im still curious about the whole TRAC thing If someone tried to remove it, then Im having a feeling that something in that is having to do with it, especially if they tried to do something to eliminate any MIL situations cause the MIL will be on if the signals are not fed back into the ecu namely the VTA2 signal and possibly the IDL2. If they did the signals wrong, there very well could be a dead short right there.

 

[Peewee]

but this I disagree with..... If it wasn't right, service manuals wouldn't supply resistance values... These values in some circuits are very important... One example is I had a car that VC to E2 had 20ohms of resistance and that was close enough to a dead short and thus fried the 5v out put...

I tihnk what Sideshow is trying to say is that some people will check for voltage, see nothing, then check for resistance, and if they see anything there (albeit 100ohms or 1ohm), they think its a short to ground.

 

[sideshow]

what im tyring to say is resistance will give u bad readings sometimes

if there is anything else on that wire or circuit u will get bad resitance readings to ground

like injectors when u measure one inejctor for resistance then on some cars
u will measre 2 or more injectors cause they are on smae circuit

i have a 200 dollar test light with voltmeter and **** on it
it will even make me coffee in the morning hehehe

i use this to test everything

once u learn how to diagnose

u will always use voltage

peewee is right where how do u know if its a short

1ohm is a short
but 3 ohms might not be a short

anyway enough of wiring 101 for dummies

its not helping the loom getting better

 

[cjsupra90]

I understand what you'll are saying about the resistance vs. voltage argument and I agree with that part, but if you checking resistance of a particular item like TPS and its unplugged, then nothing else is going to effecting it..... Also, you have no choice but to check resistances if your not getting voltage as in the case at hand..... Now why is he not getting voltage?????

On a different note, I still agree and back up the fact that he need to either take it some where or be willing to pull back the harness.....

 

[thenewmexican]

Hey Guys,
Merry Christmas to all.

Thanks for all the input, and discussion regarding my problem.
As cjsupra90 suggested, I managed to pull the wiring harness through the firewall into the engine compartment. I cut open the plastic coverings exposing all the wires on the harness.

What do I test for ??

Thanks again.

 

[cjsupra90]

Merry Christmas,

Really it was sideshow that seguested the pulling the harness apart but either way......

first thing is to be looking for any obvious damage to any wires and fix anything that you find... You will find splices here and there make sure that they are still wrapped well and not expossing and part of the stripped wiring or metal crimp used to comment the wires. You could focus mainly on the VC (blue / Red) wire but if there is damage to it, then there is a pretty good possibility that there are over problems and damage to other things that need attention. If you've ever heard the saying, "Searching with a fine tooth comb." well apply that saying here....