2001 S80 T6 with codes and transmission issues...

[agraves138]

OK will give it a shot.

[agraves138]

Ok so we swapped the Rear Driverside O2 sensor and moved it over to the rear Passenger side slot. The car continues to miss, and now the driverside cat got red hot. So far no CEL or trouble codes...

[agraves138]

Dealer advised the ECU is malfunctioning and the car would require a new ECU.... Any thoughts??

[precopster]

If swapping the O2s created a change in the CAT temperature it's definitely evidence that the O2s aren't monitoring the exhaust gas temperature adequately and are telling the car's ECM (ECU) to alter the fuel/air mixture.

At this age of car one must always suspect poor contact between the ECM and its mating connector and/or poor contact in the O2 sensor wiring. Did the dealership remove the ECM and clean the contacts?

I would personally begin this diagnostic with a good scanner even if you need to purchase one; an Autel EU-702 would be perfect as a low cost adaptable scanner.
If the above is entirely impossible at least purchase a ECM removal tool & clean the ECM connector and/or replace BOTH O2s with genuine new ones.

[lopez 62]

Hi my name is Felix. I have some codes issues. P1816. The dashboard is like crazy all the light comes on. Went i run the cars runs ok. But went i stop and star again the transmission stays on one speed only. Please if you know what could be. Please let me know.

[agraves138]

OK so here is whats been going on. I decided to send my ECM to XeMODeX for a software transfer to a good ECM. Got it back and installed it tonight. Initially it ran well and then once the car warmed up it began to stumble, buck, and run rough again, and finally just shut off. It stumbles to the point where the lights in the dash and the head lights dim along with the rough idle. I spoke to Tony at XeMODex and he said that the software transferred properly and the salvage unit I sent them was tested and in good working order. Since it's doing the same thing it did with the original ECM I have a feel the ECM wasn't the problem...and thus I just wasted $300 with XeMODex. Here is the paperwork the Volvo dealership gave me when they initially diagnosed the ECM as defective.

Diagnosis
https://scontent-a-iad.xx.fbcdn.net/hph ... 6013_n.jpg

Parts/Labor Quote
https://scontent-a-iad.xx.fbcdn.net/hph ... 3873_n.jpg

Quote Page 2
https://scontent-a-iad.xx.fbcdn.net/hph ... 2580_n.jpg

Control Module Diagnosis Codes
https://scontent-b-iad.xx.fbcdn.net/hph ... 5391_n.jpg

Back to the drawing board.

[boosted5cyl]

Oh boy. Well here's a longshot.... (temporarily) disconnect the ABS unit. Sometimes they can fail in ways that sends garbage data across the CANBUS and all sorts of weirdness happens.
Worth a shot as it's a somewhat common failure.