Civic 2003 sedan a/c wont start? Where is ECM

darksniperx

New Member
Hi,

Last year my a/c would not turn off.
This year my a/c would not turn on, I press the a/c button it turns green but nothing happens,
I googled around and got a repair manual for civic 2002-2003.
Tested fuses under dash and under hood, everything ok.
Tested Relays under the hood, everything ok.
Jumpwire compress clutch and condenser fan,radiator fan, everything ok.
Tested Heater control panel, everthing ok.

The only 2 things I wasnt able to test:

is the ECM, I have no idea where it is.
Under-dash fuse/relay box connector F (12P) could not find it.

I did find the ECU under the glove compartment , the silver gray box, but have no idea how to test it.

Any help would be appreciated.
 

RonJ

Banned
Did you try to retrieve a DTC from the heater control panel? The procedure is described on pgs 21-8 to 21-9 of the manual you downloaded.

When you press the A/C button, neither the fans run nor the compressor engages, right?
 


darksniperx

New Member
RonJ said:
Did you try to retrieve a DTC from the heater control panel? The procedure is described on pgs 21-8 to 21-9 of the manual you downloaded.

When you press the A/C button, neither the fans run nor the compressor engages, right?
Click to expand...
1) I did check it, and everything is ok, no blinking.

2) Yes, when I press the button, nothing engages.

I have also went to closest garage to check if i freon gas in my a/c. I have been told that everything is ok, that it is at the right lvl.
 

RonJ

Banned
Have tried bypassing the pressure switch or the A/C thermostat in the evaporator?


Here's how to pull heater control panel DTCs:




 


RonJ

Banned
Unplug the 2P connector for the A/C pressure switch located near the receiver/dryer. The connector has a Blu wire and a Blu/Wht wire. Use a small piece of wire or a paper clip to short the two wires in the free connector. Now start the engine and check to see if the A/C now works. If so, the pressure switch is bad. Don't let the A/C run very long because the pressure switch is not there to shut off the system to protect the compressor if the system were to over pressurize.




 

darksniperx

New Member
Hi,

I just tried that, and no response.

I have also checked the continuity on that wire, and its there.

Which means that the pressure switch should be fine.
 

RonJ

Banned
Now do the same test with the evaporator temperature sensor. Jump the Brn wire to the Lt Grn wire in the disconnected plug.





 
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darksniperx

New Member
A good question would be, how to I get to evaporator temperature tester?

Ok I see it, didnt notice the second picture.
 

RonJ

Banned
darksniperx said:
They all show 0 volts , whether the car is on or off.
Click to expand...
Describe how you are testing voltage at fuses 1 and 4.

Does the radiator fan ever run?

When you jumped the condenser fan and compressor clutch relays, what specific terminals did you jump?

 
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