Getting Code 64, Have Questions...

[afast93stang]

As the title says, im getting code 64, I did some searching but im not totally clear, it says its the IAT but ive got an 89 5.0 in my fox. Is it the ACT on my car?

If so, can it be cleaned or does it need to be totally replaced?

 

[HISSIN50]

The IAT = ACT. You can ohm out the thermistor to see if it is near calibrated, or just replace it (it isnt expensive). I would check the wiring to it real quick to make sure it's not a wiring issue.

Good luck.

 

[jrichker]

Code 64 – ACT (Air Charge Temperature) signal low or grounded. Bad sensor,
sensor wiring on pin 25 shorted to ground, or bad computer.

Note that all resistance tests must be done with power off. Measuring
resistance with a circuit powered on will give false readings and possibly
damage the meter.

The ACT is located in the #5 intake runner on Mustangs built from 86-93
. Disconnect the sensor by removing the sensor wiring connector. Measure
the resistance across the sensor pins.

Ohms measures at the computer with the computer disconnected, or at the
sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms

If the sensor resistances read good according to the table, remove
the passenger side kick panel and disconnect the computer connector.
A single 10 MM bolt secures the connector in place. With the sensor
connector still disconnected, measure the resistance between pin 25
(lt green/pink wire) and ground. If you wish, you can make your
measurements at the ACT sensor end. This will save you from
counting the computer connector pins to locate the correct one.
However, you will still have to disconnect the computer connector.
You should see 100K Ohms or greater between pin 25 and ground.
Less than that indicates wiring problems with the pin 25
lt green/pink wire shorted to ground. Note that the following
diagram on the connector displays the pins viewed from the
computer side.

See following website for some help from Tmoss
(diagram designer) & Stang&2Birds (website host) for
help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/
http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

Diagram courtesy of Tmoss & Stang&2birds

 

[afast93stang]

Heres the thing, before this, I was getting code 22 which is for the BAP sensor, I got one from Ford today (correct part #), installed it and then it threw out the code 64 for the ACT, it never gave me that code before today. I drove it around and now it is running rich and very sluggish, before the new BAP sensor it ran really good and strong but the only issue was it would rev up to 2500 rpm when the clutch was pushed in and threw out code 22 (BAP sensor). Ive already replaced the IAC and checked the TPS and im not throwing out any other codes...

 

[afast93stang]

Anyone have any ideas or suggestions?

 

[jrichker]

Get out your DVM and work through the tech note I posted. You will either find a bad sensor or bad ACT wiring.