2003 Camry 2.4L / Need Wiring Diagram of IAT

[Fecomosis]

Hello, Im in need of a wiring diagram / picture location of the IAT on a 03 Toyota Camry. Im testing out some performance parts and 1 of the parts is to put a resistor on the iat sensor.

thanks

[Brian R.]

The IAT sensor is integrated into the air flow meter. The IAT sensor contacts are E2 and THA on the AFM terminals. The resistances between these terminals are:

-4F 13.6-18.4 kOhms
68F 2.21-2.69 kOhms
140F 0.493-0.667 kOhms

If you look at the AFM connector contacts with the clip on top, the terminals are E2, THA, VG, E2G, and +B from left to right.

[Fecomosis]

Great thanks a bunch, oh btw. How do you remove those 2 pins for the IAT leads from the AFM Connector?

[Brian R.]

Don't remove them. Either splice in a resistor into the circuit to increase the resistance and allow it to still vary with temperature, or just cut the wires to the IAT sensor and splice in a resistor (bypass the IAT sensor) if you want a constant resistance. Don't alter the sensor. Make sure whatever you do is reversible.

[Fecomosis]

Ok, well now I need to firgure out what value of resistance will give me the optimium power. Is it the colder it is the less resistance or is it reversed for a thermistor? What value would you recconmend.

[Brian R.]

I gave you the resistances at various temperatures in post #2 above.

I would use a variable resistor that ranged from 0-20 kOhms or so - starting off at 2-3 kOhms or so and working up. Don't operate where you see the CEL come on.

[Fecomosis]

Great thanks a bunch mang. Have you done this modd youself? If so does it work at all?

[Brian R.]

No, never done it. Just guessing from the specifications. Don't know what to expect. Just don't do anything expensive.

[Fecomosis]

Im thinking of suping up my 03 camry because 1gear goes to 42mph at redline thats pretty good.

[WickedNYCowboy]

All I have to say is you either need forced induction or spray. If I were you would have just gotten a V6 and a blower.

[MT-2500]

Originally Posted by Fecomosis

Great thanks a bunch mang. Have you done this modd youself? If so does it work at all?

I have saw them installed with K&N filter kits.
What it does is fools the PCM into a richer mix by changing the IAT sensor reading. It just gives you a richer fuel mix but 02 sensors and other sensors may pick up the richer mix and lean it back up.
Not sure it is a good idea. Or that it helps much.
I would not use it much.

Also it may be a illegal operation.
http://www.epa.gov/air/caa/caa203.txt


Sec. 203. (a) The following acts and the causing thereof are
prohibited-
(1) in the case of a manufacturer of new motor vehicles or
new motor vehicle engines for distribution in commerce, the
sale, or the offering for sale, or the introduction, or
delivery for introduction, into commerce, or (in the case of
any person, except as provided by regulation of the Adminis-
trator), the importation into the United States, of any new
motor vehicle or new motor vehicle engine, manufactured
after the effective date of regulations under this part
which are applicable to such vehicle or engine unless such
vehicle or engine is covered by a certificate of conformity
issued (and in effect) under regulations prescribed under
this part or part C in the case of clean-fuel vehicles
(except as provided in subsection (b));
(2)(A) for any person to fail or refuse to permit access
to or copying of records or to fail to make reports or
provide information required under section 208;
(B) for any person to fail or refuse to permit entry,
testing or inspection authorized under section 206(c) or
section 208;
(C) for any person to fail or refuse to perform tests, or
have tests performed as required under section 208;
(D) for any manufacturer to fail to make information
available as provided by regulation under section 202(m)(5);
(3)(A) for any person to remove or render inoperative any
device or element of design installed on or in a motor
vehicle or motor vehicle engine in compliance with regula-
tions under this title prior to its sale and delivery to the
ultimate purchaser, or for any person knowingly to remove or
render inoperative any such device or element of design
after such sale and delivery to the ultimate purchaser; or
(B) for any person to manufacture or sell, or offer to
sell, or install, any part or component intended for use
with, or as part of, any motor vehicle or motor vehicle
engine, where a principal effect of the part or component is
to bypass, defeat, or render inoperative any device or
element of design installed on or in a motor vehicle or
motor vehicle engine in compliance with regulations under
this title, and where the person knows or should know that
such part or component is being offered for sale or
installed for such use or put to such use; or
(4) for any manufacturer of a new motor vehicle or new
motor vehicle engine subject to standards prescribed under
section 202 or Part C-
(A) to sell or lease any such vehicle or engine
unless such manufacturer has complied with (i) the
requirements of section 207 (a) and (b) with respect to
such vehicle or engine, and unless a label or tag is
affixed to such vehicle or engine in accordance with
section 207(c)(3), or (ii) the corresponding
requirements of part C in the case of clean fuel
vehicles unless the manufacturer has complied with the
corresponding requirements of part C
(B) to fail or refuse to comply with the requirements
of section 207 (c) or (e), or the corresponding
requirements of part C in the case of clean fuel
vehicles
(C) except as provided in subsection (c)(3) of
section 207 and the corresponding requirements of part
C in the case of clean fuel vehicles, to provide
directly or indirectly in any communication to the
ultimate purchaser or any subsequent purchaser that the
coverage of any warranty under this Act is conditioned
upon use of any part, component, or system manufactured
by such manufacturer or any person acting for such
manufacturer or under his control, or conditioned upon
service performed by any such person, or
(D) to fail or refuse to comply with the terms and
conditions of the warranty under section 207 (a) or (b)
or the corresponding requirements of part C in the case
of clean fuel vehicles with respect to any vehicle; or
(5) for any person to violate section 218, 219, or part C
of this title or any regulations under section 218, 219, or
part C.
No action with respect to any element of design referred to in
paragraph (3) (including any adjustment or alteration of such
element) shall be treated as a prohibited act under such
paragraph (3) if such action is in accordance with section 215.
Nothing in paragraph (3) shall be construed to require the use
ofmanufacturer parts in maintaining or repairing any motor
vehicle or motor vehicle engine. For the purposes of the
preceding sentence, the term "manufacturer parts" means, with
respect to a motor vehicle engine, parts produced or sold by the
manufacturer of the motor vehicle or motor vehicle engine. No
action with respect to any device or element of design referred
to in paragraph (3) shall be treated as a prohibited act under
that paragraph if (i) the action is for the purpose of repair or
replacement of the device or element, or is a necessary and
temporary procedure to repair or replace any other item and the
device or element is replaced upon completion of the procedure,
and (ii) such action thereafter results in the proper functioning
of the device or element referred to in paragraph (3). No action
with respect to any device or element of design referred to in
paragraph (3) shall be treated as a prohibited act under that
paragraph if the action is for the purpose of a conversion of a
motor vehicle for use of a clean alternative fuel (as defined in
this title) and if such vehicle complies with the applicable
standard under section 202 when operating on such fuel, and if in
the case of a clean alternative fuel vehicle (as defined by rule
by the Administrator), the device or element is replaced upon
completion of the conversion procedure and such action results in
proper functioning of the device or element when the motor
vehicle operates on conventional fuel.
(b)(1) The Administrator may exempt any new motor vehicle or
new motor vehicle engine from subsection (a), upon such terms and
conditions as he may find necessary for the purpose of research,
investigations, studies, demonstrations, or training, or for
reasons of national security.
(2) A new motor vehicle or new motor vehicle engine offered for
importation or imported by any person in violation of subsection
(a) shall be refused admission into the United States, but the
Secretary of the Treasury and the Administrator may, by joint
regulation, provide for deferring final determination as to
admission and authorizing the delivery of such a motor vehicle or
engine offered for import to the owner or consignee thereof upon
such terms and conditions (including the furnishing of a bond) as
may appear to them appropriate to insure that any such motor
vehicle or engine will be brought into conformity with the
standards, requirements, and limitations applicable to it under
this part. The Secretary of the Treasury shall, if a motor
vehicle or engine is finally refused admission under this
paragraph, cause disposition thereof in accordance with the
customs laws unless it is exported, under regulations prescribed
by such Secretary, within ninety days of the date of notice of
such refusal or such additional time as may be permitted pursuant
to such regulations, except that disposition in accordance with
the customs laws may
not be made in such manner as may result, directly or indirectly,
in the sale, to the ultimate consumer, of a new motor vehicle or
new motor vehicle engine that fails to comply with applicable
standards of the Administrator under this part.
(3) A new motor vehicle or new motor vehicle engine intended
solely for export, and so labeled or tagged on the outside of the
container and on the vehicle or engine itself, shall be subject
to the provisions of subsection (a), except that if the country
which is to receive such vehicle or engine has emission standards
which differ from the standards prescribed under section 202,
then such vehicle or engine shall comply with the standards of
such country which is to receive such vehicle or engine.
[42 U.S.C. 7522]


MT

[Brian R.]

I think the time at which the IAT sensor influences the mixture is under hard acceleration where the ECM overrides closed-loop. The resistor mod shouldn't affect closed-loop mixture. Then the mixture is controlled by the HO2 or A/F ratio sensor.

[Brian R.]

Originally Posted by MT-2500

...it may be a illegal operation.
http://www.epa.gov/air/caa/caa203.txt


Sec. 203. (a) The following acts and the causing thereof are
prohibited-
(1) in the case of a manufacturer of new motor vehicles or
new motor vehicle engines for distribution in commerce, the
sale, or the offering for sale, or the introduction, or
delivery for introduction, into commerce, or (in the case of
any person, except as provided by regulation of the Adminis-
trator), the importation into the United States, of any new
motor vehicle or new motor vehicle engine, manufactured
after the effective date of regulations under this part
which are applicable to such vehicle or engine unless such
vehicle or engine is covered by a certificate of conformity
issued (and in effect) under regulations prescribed under
this part or part C in the case of clean-fuel vehicles
(except as provided in subsection (b));
(2)(A) for any person to fail or refuse to permit access
to or copying of records or to fail to make reports or
provide information required under section 208;
(B) for any person to fail or refuse to permit entry,
testing or inspection authorized under section 206(c) or
section 208;
(C) for any person to fail or refuse to perform tests, or
have tests performed as required under section 208;
(D) for any manufacturer to fail to make information
available as provided by regulation under section 202(m)(5);
(3)(A) for any person to remove or render inoperative any
device or element of design installed on or in a motor
vehicle or motor vehicle engine in compliance with regula-
tions under this title prior to its sale and delivery to the
ultimate purchaser, or for any person knowingly to remove or
render inoperative any such device or element of design
after such sale and delivery to the ultimate purchaser; or
(B) for any person to manufacture or sell, or offer to
sell, or install, any part or component intended for use
with, or as part of, any motor vehicle or motor vehicle
engine, where a principal effect of the part or component is
to bypass, defeat, or render inoperative any device or
element of design installed on or in a motor vehicle or
motor vehicle engine in compliance with regulations under
this title, and where the person knows or should know that
such part or component is being offered for sale or
installed for such use or put to such use; or
(4) for any manufacturer of a new motor vehicle or new
motor vehicle engine subject to standards prescribed under
section 202 or Part C-
(A) to sell or lease any such vehicle or engine
unless such manufacturer has complied with (i) the
requirements of section 207 (a) and (b) with respect to
such vehicle or engine, and unless a label or tag is
affixed to such vehicle or engine in accordance with
section 207(c)(3), or (ii) the corresponding
requirements of part C in the case of clean fuel
vehicles unless the manufacturer has complied with the
corresponding requirements of part C
(B) to fail or refuse to comply with the requirements
of section 207 (c) or (e), or the corresponding
requirements of part C in the case of clean fuel
vehicles
(C) except as provided in subsection (c)(3) of
section 207 and the corresponding requirements of part
C in the case of clean fuel vehicles, to provide
directly or indirectly in any communication to the
ultimate purchaser or any subsequent purchaser that the
coverage of any warranty under this Act is conditioned
upon use of any part, component, or system manufactured
by such manufacturer or any person acting for such
manufacturer or under his control, or conditioned upon
service performed by any such person, or
(D) to fail or refuse to comply with the terms and
conditions of the warranty under section 207 (a) or (b)
or the corresponding requirements of part C in the case
of clean fuel vehicles with respect to any vehicle; or
(5) for any person to violate section 218, 219, or part C
of this title or any regulations under section 218, 219, or
part C.
No action with respect to any element of design referred to in
paragraph (3) (including any adjustment or alteration of such
element) shall be treated as a prohibited act under such
paragraph (3) if such action is in accordance with section 215.
Nothing in paragraph (3) shall be construed to require the use
ofmanufacturer parts in maintaining or repairing any motor
vehicle or motor vehicle engine. For the purposes of the
preceding sentence, the term "manufacturer parts" means, with
respect to a motor vehicle engine, parts produced or sold by the
manufacturer of the motor vehicle or motor vehicle engine. No
action with respect to any device or element of design referred
to in paragraph (3) shall be treated as a prohibited act under
that paragraph if (i) the action is for the purpose of repair or
replacement of the device or element, or is a necessary and
temporary procedure to repair or replace any other item and the
device or element is replaced upon completion of the procedure,
and (ii) such action thereafter results in the proper functioning
of the device or element referred to in paragraph (3). No action
with respect to any device or element of design referred to in
paragraph (3) shall be treated as a prohibited act under that
paragraph if the action is for the purpose of a conversion of a
motor vehicle for use of a clean alternative fuel (as defined in
this title) and if such vehicle complies with the applicable
standard under section 202 when operating on such fuel, and if in
the case of a clean alternative fuel vehicle (as defined by rule
by the Administrator), the device or element is replaced upon
completion of the conversion procedure and such action results in
proper functioning of the device or element when the motor
vehicle operates on conventional fuel.
(b)(1) The Administrator may exempt any new motor vehicle or
new motor vehicle engine from subsection (a), upon such terms and
conditions as he may find necessary for the purpose of research,
investigations, studies, demonstrations, or training, or for
reasons of national security.
(2) A new motor vehicle or new motor vehicle engine offered for
importation or imported by any person in violation of subsection
(a) shall be refused admission into the United States, but the
Secretary of the Treasury and the Administrator may, by joint
regulation, provide for deferring final determination as to
admission and authorizing the delivery of such a motor vehicle or
engine offered for import to the owner or consignee thereof upon
such terms and conditions (including the furnishing of a bond) as
may appear to them appropriate to insure that any such motor
vehicle or engine will be brought into conformity with the
standards, requirements, and limitations applicable to it under
this part. The Secretary of the Treasury shall, if a motor
vehicle or engine is finally refused admission under this
paragraph, cause disposition thereof in accordance with the
customs laws unless it is exported, under regulations prescribed
by such Secretary, within ninety days of the date of notice of
such refusal or such additional time as may be permitted pursuant
to such regulations, except that disposition in accordance with
the customs laws may
not be made in such manner as may result, directly or indirectly,
in the sale, to the ultimate consumer, of a new motor vehicle or
new motor vehicle engine that fails to comply with applicable
standards of the Administrator under this part.
(3) A new motor vehicle or new motor vehicle engine intended
solely for export, and so labeled or tagged on the outside of the
container and on the vehicle or engine itself, shall be subject
to the provisions of subsection (a), except that if the country
which is to receive such vehicle or engine has emission standards
which differ from the standards prescribed under section 202,
then such vehicle or engine shall comply with the standards of
such country which is to receive such vehicle or engine.
[42 U.S.C. 7522]

Reading the above code, I noticed the following are illegal:

203(a)(1) Selling a new vehicle or engine that is out of conformance
203(a)(2)(A-D) Not allow access to records or provide testing results
203(a)(3)(A) Remove or render inoperative any device before or after sale for the purpose of sale
203(a)(3)(B) manufacture, or sell, or offer to install, any part or component to bypass, defeat, or render inoperative any device installed in a motor vehicle and where the person knows or should know that such part or component is being offered for sale or used for that purpose

It does not prohibit altering your personal vehicle

[MT-2500]

Originally Posted by Brian R.

Reading the above code, I noticed the following are illegal:

203(a)(1) Selling a new vehicle or engine that is out of conformance
203(a)(2)(A-D) Not allow access to records or provide testing results
203(a)(3)(A) Remove or render inoperative any device before or after sale for the purpose of sale
203(a)(3)(B) manufacture, or sell, or offer to install, any part or component to bypass, defeat, or render inoperative any device installed in a motor vehicle and where the person knows or should know that such part or component is being offered for sale or used for that purpose

It does not prohibit altering your personal vehicle

Read section 3A and 3B real close.
I take it to read before and also after sale to owner.
But I am no lawyer.
A person can do about anyting to his car in the back yard.
But when it is operated on a federal funded highway it comes under federal rules and regulation.And also some states and citys have added some laws on it.
Remember federal laws is what done in Al Copone and some of them big old gansters.
So procede with caution.
MT

[Brian R.]

I agree - the best approach is no modification