2002 XC70 ECU Issues... worth fixing?

Trandahl · Post by **Trandahl** » 17 Apr 2014, 16:11

I bought a clean title 02 XC70 w/ 125k on it in January.

When I tried to pass my county emissions test, I learned (much to my chagrin) the CEL was disabled and there were several active codes. Since then, I've gotten busy:
-Flushed transmission; replaced crankshaft position sensor bracket
-Changed oil/filter
-Changed engine and cabin air filters
-Replaced fuel pump and filter (fuel pump was on recall and got it changed for free at dealer)
-Replaced turbo discharge hose
-Re-timed the motor
-Replaced all spark plugs

I have been eliminating the codes one by one, but these last 3 (turbo underboost, control mod performance, and sensor bank under threshold) won't go away. My last code clearing was about 400 miles ago and several sensors still aren't "ready."

I finally broke down and went to dealer. Dealer says ECU is fried and giving false codes. $1,400 for part, $500 labor. I said thanks but no thanks as I paid a whopping $3,500 for the car (now I know why).

Have you all had any success with sites like Xemodex and other 3rd party ECU repair/replacement sites? The dealer said (of course) that most people that try that route end up wasting money, and the new/repaired ECU doesn't function in their vehicle. He advised getting rid of the vehicle instead of pouring money into it.

I am willing to get it fixed, but not $1,900 willing. Just don't know how successful those products are, especially in this vehicle.

Post by **abscate** » 18 Apr 2014, 19:08

Well, unless you pass the bad karma onto the next guy, selling it is a loss.

Why don't you source a junkyard ECU and then have it programmed at dealer? Should be 600-700 usd total

Post by **oragex** » 19 Apr 2014, 09:42

Can't say for sure, but there is a chance Volvo only wants your money. Ask them if they replace the ECU and it doesn't fix the codes, if they are going to refund you. Just for fun:)

The easiest is to return the car to the seller. Looks like hidden issues that are not easy (cheap) to fix.

Post by **kcodyjr** » 19 Apr 2014, 12:00

Is there any overt running symptom?

I don't know about your state, but here in MA, once you've put a certain amount of money into trying to fix an emissions problem (CEL) and failing, they let you off the hook.

Have you looked thoroughly for a wiring harness fault?

Seems to me a "fried ECU" should have both a cause, and overt running symptoms.

Post by **jimmy57** » 19 Apr 2014, 12:18

Xemodex has a great track record. Indy shops use them for Volvo control modules all the time.
Used ECM on 99 and later can't be used without sending them to Xemodex or a couple of others that can blank them for you. Volvo dealers only have a way to clear an ECM if it is the vehicle it is harvested from. Then the ECM has to be downloaded to get software and security code load for the vehicle

Buckone · Post by **Buckone** » 19 Apr 2014, 12:23

I used Xemodex for my 2002 S60 Turbo AWD with no problem. I bought an ECU on Ebay for $28. You have to send the old and new unit so they can move the codes. They keep old unit. Be aware that you pay for shipping in your order. They send you a label or shipping info. I got in a hurry and sent the unit before getting the shipping info from them and paid twice basically. It was a pain since they were in Canada. They turned it around very quickly and it worked great. If you have never pulled the ECU be aware it takes a special tool. I made one from some online instructions with some metal strapping and rivets.

Post by **doublebug** » 19 Apr 2014, 12:34

What exact codes ECM-XXXX are left?

Trandahl · Post by **Trandahl** » 21 Apr 2014, 06:24

kcodyjr wrote:Is there any overt running symptom?

I don't know about your state, but here in MA, once you've put a certain amount of money into trying to fix an emissions problem (CEL) and failing, they let you off the hook.

Have you looked thoroughly for a wiring harness fault?

Seems to me a "fried ECU" should have both a cause, and overt running symptoms.

I have not noticed any running issues, save the turbo doesn't seem to be functioning properly... not really getting any boost or "umph" from it. Replaced the discharge/intercooler pipe recently and that did not seem to help.

I have inspected the wiring to the degree that I am capable of inspecting and didn't see anything amiss. When the dealer tore the car apart to try and find out what was wrong, he found some aftermarket wiring on the A/C relay switch and changed it out w/ factory. A/C still doesn't work, but that it the only wiring anomaly located to date.

I am TN, and w/ any CEL you fail the annual emissions test. Only certain counties require it. Unfortunately, I live in a county which does require it, but I bought the car in a county that does not. The CEL was disabled when I bought it (obviously, I did not know at that time).

Trandahl · Post by **Trandahl** » 21 Apr 2014, 06:27

doublebug wrote:What exact codes ECM-XXXX are left?

P0607 Control mod performance
P0299 Turbo underboost
P0420 Catalyst system efficiency below threshold, bank 1

And I have noticed the turbo does not seems to be... there. You can really only feel it when in 3rd gear and already going. It does not drive like a car w/ a turbo at the moment.

Trandahl · Post by **Trandahl** » 21 Apr 2014, 06:35

kcodyjr wrote:
Seems to me a "fried ECU" should have both a cause, and overt running symptoms.

Invoice from dealer:

"FOUND PERMANENT FAULTS WITH ECM. NEEDS REPLACEMENT, ALSO FOUND AFTER MARKET WIRING ON A/C PRESSURE SENSOR."