stolen ECM replacement throwing a code 48
 

Hello,

I have a 1995 Honda Civic VX, which I have been driving since 1998. Two weeks ago someone broke into the car and stole the Engine Control Module. I was able to get the part number from the Honda dealer (37820-P07-A01) and ordered a used ECM off of ebay. Now I am getting a code 48. The O2 sensor (5 wire) is about 3 years old and there was no CEL before the ECM was stolen. The car is driving poorly and the shift light (little green arrow on dash) is not coming on.

My question is, is this a faulty ECM? Any way to test it or the O2 sensor? Any other options for a code 48?

Thanks

There are two different ECU's, one for 4-wire O2 sensor, and one for 5-wire. Check how many wires your upper o2 sensor has and adjust accordingly.

Thank you for the reply. According to Honda this ECU (part number 37820-P07-A01) is specific to the 94 & 95 Honda Civic VX, which have five wire oxygen sensors.

Do you have a 49 state, non-Cali Civic? Where was it originally sold? Because the p07-a01 is for the Cali VX and there is a p07-a00 that is for the non-Cali VXs, I believe. I would not expect the dealer to know, necessarily. These cars are over 20 years old and beginning in 1996 with the HX and OBD2 there was no longer a cali/non-cali distinction. If you have the wrong VX ECU for your VX you will get codes, because the Cali VX was not able to do lean burn (SMOG rules).

Oh! And it might also be the A00/A01 difference might be between auto and manual transmissions. Do what Balto is suggesting, or take it back to the dealer armed with these new possibilities and see what trouble shotting they can do. They should get it right.

Thanks for the reply.

The car is a 49 state car.

When deciphering the ECU part number:

37820 is Engine control module

P07 is manual; P06 is automatic

A01 is 94-95 49 state emissions standards
A00 is 92-93 49 state emissions standards
L01 is the 50 state emissions for 94-95
In general 00 is 92-93 and 01 is 94-95. L is 50 state emissions, C would be from Canada.

The part I have is the correct part for the car. It is a used part and throwing a code. The car was functioning perfectly with the original ECU so I need to know if this code is due to the replacement ECU and how to test for that.

Great info. Thanks for sharing your research. The standard test for the 02 and the ECU in the Honda FSM is "replace with known good"--as if the FSM assumes you are at a dealership and have ready access to replacement parts or something, lol.

Check connections to the ECU, making sure the tech really hooked it up correctly. Check the O2 as well. I know it was good before, but there are coincidences and maybe something is suddenly registering differently,or has suddenly failed. My OEM starter motor was failing intermittently and I carried around a wrench to tap it everynow and then so it would work normally. Three years ago, I swapped my transmission, and my starter problem went away permanently. Then, suddenly, the slave cylinder on the hydraulic clutch mechanism had a complete failure. Ghosts in the machine do odd things.

Thank you. I appreciate the advice. I will double check the connections on the ECU and check out the O2 sensor. If you happen to know which ECU connector has the O2 wires, I can focus my efforts there.

The car is running really rough, no power (even less on hills than it had before), and the shift indicator light isn't working. I'm guessing the O2 sensor issues are to blame for the lack of power but add the nonfunctioning shift light and it makes me think there is something wrong with the ECU.

Unfortunately, while I have insurance, the part is so expensive that they won't cover it without totaling my car (and it still won't be enough) and there is no equivalent available from the aftermarket shops.

Thanks again for the reply.

It is definitely suspicious. The ECU is a suspect for sure.

Have you physically popped the hood and LOOKED to see if you have 5 wire o2?

Yes, it is the five wire oxygen sensor that is standard for the VX. I replaced it about three years ago. The car was running perfectly, the ECM was stolen, I replaced it with the exact part number for my vehicle, and now it is throwing a code and not running well.

On page 11-38 of the 1992-1995 USDM Honda FSM Code 48 is identified as a LAF sensor circuit problem. The first suggestion in te trouble shooting flow chart is to reset the ECU. And all the solutions in the flow chart are either (1) replace the sensor, (2) replace the ECU, or (3) find and fix an open in the circuit.

That is exactly what I was looking for! Thank you so much!