Here is the situation:

2001 civic LX sedan, A/T

purchased car at auction to make a safe driver for my niece (her parents just can’t afford to do so)

Car is throwing a P1607 code, “internal ECM failure”. Previous owner had swapped in a salvage yard ECM, but car wouldn’t start. So, he put the original ECM back in. Obviously he neglected to realize that the reason the car would not start was because of the chip in the key not matching the salvage yard ECM. He did include the salvage yard ECM. So, I swapped the chip from the original ECM into the salvage yard ECM. Car starts, runs fine, but still has the CEL on, and code reader continues to pull the P1607 code. One thing I did notice, was the previous owner was not what I would call thorough in his installation of the ECM in the swap, and neglected to bolt down the ECM properly. Which looks to me is where the ECM grounds itself properly. OK so, it is possible, that both ECU are damaged, but I wouldn’t say probable? ECM communicates with the scanner, no problem, car runs great aside from the CEL. However, I don’t want to put her in a car with the CEL on, b/c I need her to not ignore it. Need it off, and then when it comes on I can save her car. Is it possible, there is some other issue that could cause this P1607 code? Possibly the MICU? I am not entirely up to speed with the function of the MICU, but maybe? A relay, or gizmo somewhere else? Does the brain trust here think that the likely hood that the previous owner not properly bolting in the ECM, caused him to damage the 2nd ECU. Alternator voltage is within reason, so I don’t that is killing the ECMs. I have way too much money in this car now to give up on it, just too deep in tires, windshield, timing belt, etc….

 

Can someone help with the abbreviations on the pin out diagram for what should be hot and what should be ground, so then I can at least verify proper voltage to the Ecm.

 

Looks like no one is gonna respond anyway, but checked the voltage supply to the PCM and compared against battery voltage. Batt voltage 12.3v, pcm voltage 11.79v, so I have half a volt drop, is that enough to make the pcm mad?

 

01-05 are junk and not worth the money necessary to fix any electrical problems they have related to the ecu or micu. You're only throwing more money away.

 

Thanks Chrisfrom1986, that was incredibly helpful…..

 

Hope your niece doesn't get stranded on the side of the road with a car neither her nor her parents can afford to fix. You ready to dump another 2-4k in screwing around with immobilizer issues?

 

Move along, I could afford to buy her whatever I wanted to. I choose to let her destroy a beater as a first car. 2-4K for immobilizer, really….. It’s a single eeprom chip, that can be soldered in 5 minutes, or removed all together. What a douchebag…..

 

Ok buddy. Not my fault you didn't research before wasting all that money. 06+ civic or accord if you want reliability.

 

Sounds like a perfect starter car to me.

Let me see what the FSM has to say about that code.

Only thing listed is clear the code. Cycle the key off then on. Wait 40 seconds with the key on then check to see if the code returned.

If the code returns replace the PCM with a known good PCM.

 

Deleted

 

RyanTheGreat, thanks for the reply. Seems a salvage yard PCM is in my future, or $180 bucks to send the one I got off for repair, just seems strange to get 2 bad PCM in a row.

 

Worth a shot. Wrecking yard will probably want $30. Will need to program the immobilizer again.

I totally feel the dumping money into a 20 year old car to restore it for someone else to drive. You can get deep into some of these repairs to make a solid car again. Still cheaper than a handful of car payments.

 

I would focus on the grounds. Could be a case of the green krusties.