V70R DTC EFI666 TCU error RESOLVED, TCM glitch

Anarchist · Post by **Anarchist** » 11 Jul 2013, 06:44

Hi Everyone,

I am hoping that the collective wisdom can be of some help to me here as this is the nexus for all stuff Volvo-related. I am a bit of a noob when it comes to cars with "brains".

I have a 1998 V70R (Motronic 4.4) with the MIL on and the DTC EFI666 (read by a complex OBD reader at a friendly independent service centre). This seems like a generic "something is wrong" code. The car is driving fine. I did a search and found nothing definitive.

As far as I can tell the fault is not in the ECU, because the OBD reader/scanners I have tried don't detect that the MIL is on from the ECU. If gets more complicated especially if "EFI666" is the same as P0666 (which would be a fault in temp circuit of the TCU/PCU). (Does that make sense?)

I am suspecting that there is a fault in the TCU. My questions are:
1. Does anyone have any experience with dealing with the EFI666 code and how to remedy it?
2. Is the '98 V70R TCU (PO9442489) in anyway "more special" than the TCU from a '98 S/V/70 T-5 or similar?
3. I have seen that there Japanese Aisin TCUs and Japanese ones. What is the difference?

I appreciate any help. All part of the learning experience...

Thanks,
Peter

Anarchist · Post by **Anarchist** » 20 Jul 2013, 06:52

So for the sake of someone else who gets a similar problem, here's what I found.

The 666 code is the ECU saying that there is a fault with the TCM. It is not the same as the OBD2 standard PO666 code (it wouldn't be that easy!).
It turns out that my TCM had 2 other faults codes: 411 (TCM EEPROM MEM fault) and 213 TP sensor signal. There was/is nothing wrong with the TPS. The codes were cleared and didn't come back. I suspect that whilst I had to move the car (getting from P to N) and reconnecting the battery momentarily to get the shift lever to move upset the TCM.
The TCMs are more-or less the same for the 4 spd FWD cars. The AWD TCM is only replaceable with another AWD TCM. Still not sure of the difference between the Japanese and Belgium ones.
At the end of all of this, my V70R no longer needs a PCV service and doesn't leak oil from the oil cooler lines (replaced with some suitable hose and quality hose clamps). Cutting/grinding the oil line crimps, with the hoses in the car and attached to the oil thermostat housing IS possible!!!

Post by **abscate** » 20 Jul 2013, 07:51

Thanks for closing loop on thread - sorry no one here was able to help.

But..you are back on the road !!

Anarchist · Post by **Anarchist** » 20 Jul 2013, 20:17

No problems at all! I just want to document the experience for others. I did find that the eBay wifi ELM327 OBD2 reader I bought was limited in its use in this case. Partly due to the non-OBD2 compliance of the 1998 electronics and the proprietary Volvo codes but also it couldn't communicate with the TCM. There is a list on this site with the conversions but I think 97 and 98 are "troublesome", orphan systems. Hope this all helps! Now to continue onto Stage 0...