01 accent no power

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LameBMX

okay first off i got this car totaled for a couple hundred bucks ... im
poor what can i say ...01 accent 1.5l sohc G engine

wiring harness was sheared behind the drivers side headlight ... some
morons decided to have tons of pairs of wires going through so some can
be hooked up backwards ... car ran fine rear-ended someone ... ran fine
until she washed the car and shorted out the wiring harness (wasnt
completely sheared but cut into all the wires real good)

now the car seems to be limited to 2-3k rpm (where do i hook up a tac?)
and has low power ... every now and then it will go with full power but
only for about 1 city block ... front oxygen sensor needs replaced (if
the heating element isnt burned out im gonna try giving it a good
cleaning if applicable)

i swapped around one set of wires for the MAF and it had really good
power for about a 2 block trip and then returned to normal ....

more than half the time it will rev up to high rpm's when its just
sittin in the driveway ...

autozone gave me 2 o2 sensor codes forget exactly what they was

other than passenger side fender and the hood the car is in great shape
.... drives and handles good ... alignment is pretty decent feeling but
steering wheel is turned

any help would be greatly appeciated ... i know how to use my multimeter
so i would prefer specs to check a sensor as opposed to just saying to
replace the sensor (haynes normally has these specs and a lovely current
flow diagram .. but there is no haynes for vehicle ... any other repair
books that would have that sort of information?)

and thanx again for even looking at this post

jerry
 
Since you've got harness damage, first check to see that the wires to the
oxygen sensors are the proper wires. You can find schematics at
www.hmaservice.com. Once you've selected Web Tech, your vehicle and
engine, click on the ETM tab. The schematic you'll need is the MFI
schematic in the fuel section. The numbers at the connectors represent
the pin location in the connectors.

You should have battery voltage across the heater wires with the key on
and the engine running.

The other wires are oxygen sensor output, which will need to be checked
for voltage cycling between 0v and 1v while the sensor is plugged in.
With the car hot and idling, it should cycle across 0.5v at least once
every three seconds.

The first place to check should be in the area of the wire repair. The
washing of the car seems to hint that water got somewhere it wasn't
supposed to. Also check to make sure bare wiring isn't rubbing on metal,
grounding it.
 
okay ..
front 02 sensor (read bad before the wreck) is givin me about 800mV at
idle ... i also ran it without the front o2 sensor in just to make sure
cat/exhaust wasnt clogged and no change ... i keep thinkin MAF sensor
.... it checked out fine except MAF term 1 to ground read at 10k ohms
(says it should be open on webtech) so i jumpered from MAF term 1 to ECM
37 (same color wires as a double check .. hard to count under the dash
with a flashlight)

did not check voltage drop across o2 heating elements

all wires have been reconnected and have survived another car wash ...
however there were numerous pairs of wires that could be crossed wired
.... ive solved 3 pairs for certian one blinker .. one for starter relay
.... and a 3rd for MAF (org blk line dont remember its term but when
mixed i lost proper power to radio and door buzzer)

looking at troubleshootin common items for high idle and engine
hesistation include ( i get better gas mileage in the city at around
30mpg keeping the rpm's as low as possible

ECT sensor ( does hyundai use different metals to induce voltage when
they are at different tempratures ... if so what should be a normal
running voltage betweent the two sensor portion)

injectors

PCM

IAT (normal thermsistor resistance on a cool day? had 5v on MAF term 2 )
TP sensor ( resistance shot off range around last 3rd and not enough
hands to change ... assumed it was workin okay, what sort of resistance
range should this be at

sorry about being a pain, but its the best way to learn about a new vehicle
 
Your O2 should be fluctuating, not steady. If it's steady, you have a
problem and need to find it. Could be the sensor, an exhaust leak, the
wiring, or some other problem entirely.

My presumption is that the water temp sensor is bimetal, but I've never
attempted to look at one. It is supposed to change resistance depending
on temp.

It will be very difficult to check individual items with a voltmeter,
especially in the fashion you suggest. Ideally, you'd hook up a scan tool
(which I'm sure you don't have) and look at the readings and flag anything
which looks suspicious.

One of the difficulties here is that it's difficult to know where to send
you. On the one hand, an O2 fault code almost always points to a faulty
O2 or leaking exhaust, but on the other hand, your case suggests some
issues with the wiring. So I'm reluctant to send you into a painstaking
inspection of the components with a voltmeter.

Not seeing the wiring repair work, it's difficult for me to know how the
repairs were made and how well they were sealed. This can have a great
deal to do with how water intrusion would affect the circuits in question.
I guess you need to decide how sure you are that the wiring repairs are in
good condition and correct, and let that be your guide as to whether you
should start investigating elsewhere.

Hope this helps.
 
hello,
well no scan tool i can just sit and use means im stuck with a
multimeter. i found a lovely section on webtech (shop) which tends to
have more info i can check myself. MAF sensor seems fine. according to
routing diagrams there should be nothing wrong with engine harness since
it comes from the middle of the firewall and the one with issues came
from the drivers side fender to behind the drivers side headlight (where
it got messed up). and all that should be on that harnes are accessory
items ie radio power turn signals headlights etc.....

car did spend a few months with a cold air intake and a huge exhaust (
exhaust is still on it )

if temp sensor changes resistence then it is bi-metal

would a faulty o2 sensor cause the engine to not rev past 2-3k (i will
tach it when i can find where to attach multimeter for tach input .. has
rpm sensor ) I myself have never seen an o2 sensor cause that much
performance... the plugs are decent to poor condition .... wires are
2.75K to 1.41K ohms ... the engine will rev up when there is no load on it

current codes set are

P0562 System Voltage Low (my subs drop battery to 10v in about 2 seconds
with engine off ... running with subs off does not affect perfomance) ..
also i did not find this on WebTech

P0136 Oxygen Sensor Circuit Malfunction (Bank1, Sensor2)

P0134 Oxygen Sensor Circuit Inactive (Bank1, Sensor1)

P0507 Idle PRM Higher Than Expected

none of these items seem as though they would cause this much of a
perfomance issue

Lastly i have been making sure to tell everyone about this level of post
warranty service with you here at the newsgroup helping people and the
WebTech ... again i have to say wow i would never have expected this
level of service for free for a 5 year old car with 45K miles that has
been totaled 2 times now ( ps last wreck was against a new chevy malibu
and it had to get towed away )

sincerely

jerry
 
You're not fully out of the woods with the O2 sensor. The engine harness
(the one that was cut) provides some power to some of the control harness
(the one coming through the firewall and going to the sensors) items.

I'm not able to check code info right now, but the O2 codes suggest a
problem with the front O2 being properly connected. I'd be sure to check
this fully like I described earlier.

For the P0507, check to be sure the idle actuator is plugged in and wired
correctly. Also check to be sure that the throttle cable is not
misadjusted and holding the throttle partially open.

For not going over 2-3k, if the engine is running smoothly, I'd check fuel
pressure and cam timing. I did have a really oddball case where the front
O2 on an Elantra caused an incredible hesitation on acceleration. The
manifold cat had been replaced and the tech who swapped to O2 bent it.
Took me a long time to find the problem. But I do suspect your O2 issue
isn't the full problem and probably isn't the main problem, based on your
description.
 
yes i doubt the o2 sensor is the main issue ... front o2 sensor heater
was receiving 18v (odd that it was a good 5v above battery voltage )
.... couldnt get a good connection to test it plugged in though .... fuel
pressure is something im fairly certian i cannot test myself , cam
timing i assume to be mark on cam aligned to mark on head with piston #1
at tdc .. hope thats correct for the vehicle ... so i guess its back to
the whole game plan of just switching matched pairs of wires around
until something works ... also i dont know if i mentioned that on some
occaisions (rare) the engine will have proper power for about 1 city
block and then returns to its current state.... throttle was fully
closed i instected all that while testing the MAF and TPS today .. man
why couldnt they have used less identical pairs running through there
.... or a current flow diagram with wire coding on it ...
thanx again
jerry
 
What's your battery voltage with engine running? 18V at O2 is definitely a
problem. Do you think it's possible the alternator is overcharging?
 
battery voltage was right around 12v .... but that voltage was checked
only with key on not while engine was running ... know of any voltage
supply wires colors that ran through the fender off hand ... im just
gonna resume my original plan of slowly swapping connect pairs and see
what makes a difference, hopefully single pair will make noticable
difference if its multiple pairs that are improperly connected
 
assuming the cam timing uses the trailing mark (second mark) and that
mark straight up ( red mark on head pointed straight up) when @ tdc via
timing marks on balancer... its spot on ... belt feels good also ...
double checked wires and i could not find any mixed ... no signs of
head(gasket) failure .. oil is oil and water is water ... nothing out
the exhaust ... does this sound like a possible ECM failure?
going to fog intake area with starting fluid see if i got a leak around
there
 
well no change in engine idling so i highly doubt an air leak .... fuel
pressure seemed okay maybe a little high (finger pressure test .. not
accurate but i know its not like 120psi or like 10 psi either .. so how
much would a new ecm be selling for these days?

thanx again for all your help ....
jerry
 
New ECMs are about $600 to $1000 if I remember correctly. ECM failure rate
on Hyundai is very rare, and when it happens, it is often caused by another
component. You'll want to be absolutely sure it's the PCM prior to
replacing it.

Did you manage to check battery voltage with engine running? An
alternator charging at 18v will blow up solid state components faster than
you can say "holy...
 
yes battery voltage was at 12v ... i checked it right after checking the
o2 sensor ... it wasnt a 12v voltage drop i opened the circuit for it (
couldnt get positive contact to the heater wires ... or heater was a
short (kinda tough to be short and have resistance though) but if there
was other loads on that line then o2 voltage drop could be 12v and
checking open circuit would have 18v ...
 
but what im kinda thinking ... you said there are sensor power wires
running through the area that took damage ... then friends wife washed
the car ... power line from ( iat ... coolant temp ... others?) will
have + from the computer through the damaged area ... when area got wet
they got shorted from the sensor they was sending power too ... increase
current through the pcm for that sensor ... fry pcm ....

now the low failure rate i like ... increases chances of finding a good
one at a bone-yard ... but i would also like to have a 3rd party check
out the re-wiring (if you cant find something ... someone else normally can)

thanx
 
The power wires there aren't actually in the control harness, they're in
the "engine" harness (which doesn't actually go to the EFI components). I
believe the two harnesses plug together inside the car and power is
connected to the control harness there. Another thing to think about is
to check the ground points and make sure the wires appear to be intact and
that the ground lugs are making good contact with the body.

It will take some poring over the schematics to see which specific wires
bring the power into the control harness, and I think it's even more
difficult online because the pages don't have links to the other pages.
Another set of eyes is always a good idea, however.
 
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