VX ECU Info, Please add yours!

[Superfuelgero]

What started it all:

Originally Posted by basjoos

The main difference is that the UK ecu allows lean burn above 2500 rpm, which the US version doesn't. So, combined with the aerocivic's low drag, allows it to cruise along in lean burn on level roads at over 90 mph.

My 92 USA ECU allowed this too (drafting) I've since swapped to UK also, will report difference.

What I have so far:

Picked up a couple extra ECU's to look at specific differences.


Close up


Inside

USA


UK

Notice the lack of HIC3 AP Sensor in lower right hand corner.


Note on the PA
The atmospheric pressure sensor, also called ''barometric pressure'' or ''PA'' sensor measures a much narrower range of pressure centered around atmospheric pressure. It is used to adjust the fuel mixture to account for differences in air density due to altitude or weather. This is in conjunction with the MAP sensor.

Shift light
Looks like the EDM ECU does not have one. I'll swap out to the other and confirm.

Specific differences:

USA, 1992 Federal

• 37820-p07-a00 / ard / 670-108387
• Ic1 m66207-211 / 223528g
• Ic2 m66201-218 / 233512g
• Has PA sensor

Originally Posted by slownugly

All 4 of my p07-a00 match yours with the m66207-211 and m66201-218 chips and have the sensor.

Originally Posted by slogfilet

37820-P07-A01
670-740416 AUS
IC1 - M66207-302 / 4012354G
IC2 - M66201-248 / 4112356G
It *does* have the PA sensor.

Lithuania

• Code: 37820-p07-g02 / auu / 673-301997
• Ic1 m66207-316 / 4012352g
• Ic2 m66201-248 / 4112356g
• No hic3 pa sensor ic

UK

• Code: 37820-p07-g02 / auu / 673-301694
• Ic1 m66207-316 / 3462357g
• Ic2 m66201-218 / 405235?g
• No hic3 pa sensor ic

Originally Posted by slownugly

My p07-g01 has the numbers 673-202114 on the outside case id. It does NOT have the sensor. Chip numbers are m66207-252 and m66201-218.

Originally Posted by greasemonkee

German:

Code: 37820-P07-G01 / ATT / 673-200257
Ic1 M66207-252 / 2272354G
Ic2 M66201-218 / 243517G

----No PA sensor------

Gen info on this:


Back Ground:

ECU Part Numbers
All Honda ECUs have a part number which is located on the side of the ECU and inside the ECU on the connector. e.g. 37820-P72-A01

The part number consists of three components:

Honda's part number for ECU, which is always 37820
Three characters (which are loosely related to the model of car/engine). e.g P72
Three characters (which are the revision of the ECU) e.g. A01 or G52
The middle three characters are the most useful to identify what the ECU is. Different generation ECUs may use the same characters. e.g. a P72 OBD I ECU is different from a P72 OBD II ECU. Here is a list of common ECUs:

The last 3 characters are broken down into 3 parts. "A" generally is used for US ECUs. "G" is European, and "J" is Japanese. There are other versions of this, but you get the idea. The second digit "0" typically means manual transmission, where a "5" means automatic transmission, and the last digit "1" is the version number.

• 37820-p07-C00 = canadian vx ecu
• 37820-p07-000 = obd1 jdm equivalent of vx ecu
• 37820-p07-A00 = vx 49 state 1992-1993
• 37820-P07-A01 = vx 49 state 1994-1995
• 37820-p07-L00 = California vx ecu (version 1)
• 37820-P07-G02 = UK/ Belgium/ Australia VEI (version 1)
• 37820-P07-G02 = UK/ Belgium/ Australia VEI (version 2)
• P84 is 92-95 OBD-1 JDM Civic ETi VTEC-E automatic

Emissions changes in 1994
-Cat must last 100k mi instead of 50k mi
Model year...Typical Cut Points...Well-tuned engine

..............CO%.....HC ppm..........CO%.....HC ppm

1981-93..... 1.0-2.5... 200-300..... 0.0-0.5... 10-50

1994 & up..... 1.0-1.5... 50-100..... 0.0-0.2... 02-20

92-95 OBD1 Civic VX (D15Z1)

Unique in that it has two 66207 processors (one presumably for the wideband O2)

Note: 303 P07 Code is very similar to 304 P28-A01 Code, at least vectors are the same!

RAM

Location Bytes Description Notes
00CC 1 Speed sensor Km/h
00D9 1 ECT sensor 0v-5v 0x00-0xFF
ROM

Locat Bytes Description Notes
1292 1 Vtec Coolant Temp Check (0xD8 enables, 0xFF disables)
1997 1 Speed limiter Value B7 is 183 km/h (114mph); FE is 254 km/h (158 mph)
1998 2 Speed Limiter Routine Bypass Change from jge label_something to two NOPs (00 00) to disable speed limiter
2BA3 2 Checksum Jump Instruction Change JEQ 2BB6 (C9 10) to SJ 2BB6 (CB ??) to disable checksum
60E6 1 Vtec Enable (0xFF enables, 0x00 disables) need to verify ?
60E7 1 Knock Enable (0xFF enables, 0x00 disables) need to verify ?
60FA 1 Vtec VSS Check (0x00 enables, 0xFF disables) need to verify ?
60FB 1 Debug Mode (0xFF enables, 0x00 disables) need to verify ?


If anyone has any of the other ecu's, please open up add report back so we can build this data out.

[slownugly]

sounds like a good thread. i picked up a euro p07 in hopes of seeing some changes but ive just been too lazy to swap it out.

I have 4 p07-a00 and 1 p07-g01

[NachtRitter]

Interesting information!

[Superfuelgero]

Originally Posted by slownugly

sounds like a good thread. i picked up a euro p07 in hopes of seeing some changes but ive just been too lazy to swap it out.

I have 4 p07-a00 and 1 p07-g01

If you get a chance open them up and get the chip #'s and see if the PA sensor is there too please.

From my reading thus far, looks like the XXX large number on the IC1&2 is code related. Hoping to confirm this by gathering more info.

Looks like the EDM doesn't have the shift light either.

[slownugly]

Will do. I'll try and get them all tomorrow

[War_Wagon]

I've got a Canadian '92 VX, I'll see if I can get to it tomorrow and pull the ECU.

[slownugly]

All 4 of my p07-a00 match yours with the m66207-211 and m66201-218 chips and have the sensor.

My p07-g01 has the numbers 673-202114 on the outside case id. It does NOT have the sensor. Chip numbers are m66207-252 and m66201-218.

I also have 2 other p07s in my cars. If I get a chance I'll check to see if they are different than the other federals but I doubt it.

[Superfuelgero]

Originally Posted by slownugly

All 4 of my p07-a00 match yours with the m66207-211 and m66201-218 chips and have the sensor.

My p07-g01 has the numbers 673-202114 on the outside case id. It does NOT have the sensor. Chip numbers are m66207-252 and m66201-218.

I also have 2 other p07s in my cars. If I get a chance I'll check to see if they are different than the other federals but I doubt it.

Awesome!

You wouldn't happen to know if any of these are 94-95 would you? I suspect that the code changed then due to emissions.

War wagon, that'd be great. I wonder where the Canadian falls in with the 3 types.

General note on the UK: The pedal feels less "dead" than the US version. It feels like the lean burn afr isn't as deep. The window feels about the same, but comes on earlier. I will need to get a wider range wideband to confirm, my AEM tops out at 18.

[slownugly]

Originally Posted by xntrx

Awesome!

You wouldn't happen to know if any of these are 94-95 would you? I suspect that the code changed then due to emissions.

War wagon, that'd be great. I wonder where the Canadian falls in with the 3 types.

General note on the UK: The pedal feels less "dead" than the US version. It feels like the lean burn afr isn't as deep. The window feels about the same, but comes on earlier. I will need to get a wider range wideband to confirm, my AEM tops out at 18.

The drivetrain in my sedan is from a 94 vx so that should be an a01. I'll have to check. My vx is a 93.

Dang. This thread might light a fire under my a$$ to swap my ecu in. My afr goes to 21.9

Have you noticed any difference in mpg numbers yet? Another thing to think about is the kind of gas they use in Europe. I think the quality of gas at our pumps is a lot worse than Europe. Just thinking about if they have different map and timing tables that are more aggressive.

[Superfuelgero]

Mpg results:
-Low speed 1-2mpg less
-High speed is 1-2 mpg better

Reason:
Torque curve is raised. Torque: 98 lb/ft at 4,800 rpm, vs (97 lb/ft at 3,000 rpm USDM).
This is why the VEI has a lower final drive (3.72 vs 3.25).

Note:
VEI 98 octane specified. I went to 93, still have some ping under high load.

Summary:
Switch to VEI if cruising at high speeds. This in a D15z1 powered HF would make for amazing mileage at 75mph. For me, I'll probably switch back since I rarely break 55 (USDM speed limit at the time).