The Mysterious ME7

[Mart5in]

Well, new fault has developed on my T5 V70 in the last few days.

Pulled out to overtake a car in 3rd, got up to about 5500rpm and was a huge bang and the car suddenly lurched forward. initially I thought the timing belt had failed or jumped a tooth! but it hasn't so that's some good news.

Being smart (arse), like I am, I disconnected the MAF (this has given me similar symptoms in the past) but the car still does it with the MAF unplugged. So I guess my MAF is fine.

So I did a DIM readout. frustrating I can't read the codes but the modules with faults are:

ABS ABS
SRS Airbags
ECM Engine Control Module
CEM Central Electronic Module
DDM Driver Door Module
CCM Climate Control Module
UEM Upper Electronic Module

I've highlighted in bold what modules I think are likely to be responsible. The only code I can pull with a generic reader is P1603 and it's not triggered but "pending".


Now, even when driving gently, it feels as though it's windy outside. like juddery.

I did have "STC Service Required" display and the STC disabled itself and put the light on the dash. It's not come back though.


Any clues? haha I knew I should have kept my 850!

[Orca2]

A big bang at 5500rpm sounds a lot like a burst turbo pipe or intercooler, i take it you have checked them over, stc flashing up at high revs can be a split abs ring, they go at high revs if they are sufficiently corroded and the dstc system thunks you are in a skid because it cant read the speed on one of your wheels correctly.

[Dangerous Dave]

As above, a loud bang would suggest an issue with the turbo piping. Check all the intake hoses and the intercooler (they can split at the top or bottom). Be aware that they can split in the most hidden places.

[MoleT-5R]

As the above replies have already stated, this sounds very much like a boost leak due to a burst pipe/hose blown off fitting or a split intercooler, all of which I have had in the past with different models. As dave mentioned, some boost leaks/ split hoses can hide very well, our V70R AWD blew it's lower IC hose off and when you quickly looked underneath all looked normal till closer inspection after a bit of head scratching. Good luck finding your issue and I hope it's just something simple like we've mentioned.

[Mart5in]

Well it looks like I'm going to be busy today then! hahahahah :)

I'll get the pipes off and check all the clamps and go from there.

[Mart5in]

The only thing I'm questioning myself is, even when driving really gentle off boost, it still feels "windy" outside - intermittently.

[Mart5in]

Okay so I've done some brainstorming (Is this still PC? lol) with a few people online so, armed with a bluetooth code reader, I've found that when the car misfires the downstream lambda sensor shows 0V. Also when the car is idling, it hiccoughs occasionally - again the lambda reading is 0v.

My throttle position is perfect, the range is 2.3% closed and goes up to 100%.

When the lambda isn't showing 0v, it's between 0.7 and 0.9V.

So my guess is that I'm getting fuel cut when the lambda reading is 0v. I've either got a broken wire (which I can't see physically) or the lambda sensor is dying. I'm at 100,000 miles so I'm placing my bets on the sensor itself.

My laptop arrives soon, I'll be able to do proper logging with that :)

[M-R-P]

All the boost pipes OK then?

[Mart5in]

All the boost pipes OK then?

Yes they all seem sound.

I diconnected the BCV and ran wastegate pressure at 6psi ish. it still does it.

Also it still does it off boost driving normally.

[Mart5in]

Okay right, I'm stumped by the lambda thing now.

I'm just going to wait for the laptop and do this properly haha.

[jamesy12345]

Just a thought but the oxygen sensor may not be defective - maybe it's just trying to rectify the result from another fault. P1603 relates to ETM according to internet search?

[deathrider311271]

i had a loud bang when one of my ETMs failed, also too out my spark plugs, lambda turned out to be a faulty MAF that caused it. Bosch paid 80% of my repair bill as the MAF was only a few weeks old

[jamesy12345]

If any use...
http://xemodex.com/us/pdf/ETM%20Flow%20Chart%2099-00-new-final.pdf

[LeeT5]

Well, new fault has developed on my T5 V70 in the last few days.

Pulled out to overtake a car in 3rd, got up to about 5500rpm and was a huge bang and the car suddenly lurched forward. initially I thought the timing belt had failed or jumped a tooth! but it hasn't so that's some good news.

Being smart (arse), like I am, I disconnected the MAF (this has given me similar symptoms in the past) but the car still does it with the MAF unplugged. So I guess my MAF is fine.

So I did a DIM readout. frustrating I can't read the codes but the modules with faults are:

ABS ABS
SRS Airbags
ECM Engine Control Module
CEM Central Electronic Module
DDM Driver Door Module
CCM Climate Control Module
UEM Upper Electronic Module

I've highlighted in bold what modules I think are likely to be responsible. The only code I can pull with a generic reader is P1603 and it's not triggered but "pending".


Now, even when driving gently, it feels as though it's windy outside. like juddery.

I did have "STC Service Required" display and the STC disabled itself and put the light on the dash. It's not come back though.


Any clues? haha I knew I should have kept my 850!

The mistake you made here was disconnecting the MAF and driving, then pulling the fault codes! Obviously, your now going to have a MAF related fault code because you disconnected the MAF and drove the car BEFORE pulling the codes. You should have pulled the codes first.

Unfortunately, this now means your going to be pissing in the wind on this one. You'll need to ignore ALL the codes, especially the first 2 and last 4. The only modules your interested in will be the ECM and CEM.
The best thing to do would be to have a good general look over the car and look for anything obvious (which we'll assume you've already done). Then make a note of all the fault codes then erase them ALL.

Road test the car by driving it normally for approx 10-20 miles. Avoid high boost until the car has warmed up to engine temperature, no need to thrash it!! You're are trying to replicate the fault, not kill it!
Once back home, plug in the diagnostics (without switching the car off) and read the codes. Make a note of the codes and then report back.

Points to note: If the timing belt broke the symptoms would be ALL dash lights 'ON' (like the ignition is on but engine not switched on) and the car would instantly start to slow down, no matter how much you press the throttle. You would then coast to a stop and the engine would not restart. When cranked, it would sound similar to pulling out your plugs and cranking over but with a little more resistance.

P1603 does point to ETM (Electronic Throttle Module). However, before you reach for the spanners it will help if you can be a little more specific on the fault code. The code is one thing but what does the fault description actually say?

...and lastly, don't assume anything! Just because you've disconnected your MAF and it still drives the same, doesn't mean your MAF is ok. Believe it of not, there is actually a correct way to diagnose a faulty MAF! :smileypul

[Mart5in]

Well I went out to the car last night and it started, and cut out straight away. it restarted and cut out again.

P1603 - Throttle Unit Internal Fault.
P1609 - Throttle Unit Internal Fault Signal too low or missing.
P0121 - Throttle Pedal Position/Switch A Circuit Range.

However, erased the codes and started the car and it's been how it was. Still a bit odd and no EML lit or codes stored.

Laptop and vida should be here on thursday though :D

[LeeT5]

Well I went out to the car last night and it started, and cut out straight away. it restarted and cut out again.

P1603 - Throttle Unit Internal Fault.
P1609 - Throttle Unit Internal Fault Signal too low or missing.
P0121 - Throttle Pedal Position/Switch A Circuit Range.

However, erased the codes and started the car and it's been how it was. Still a bit odd and no EML lit or codes stored.

Laptop and vida should be here on thursday though :D

This indicates a poor connection and a bad live/earth.
I would unbolt the ECM and carefully unplug the module. Have a look inside the plug and make sure there's no corrosion in the plug and on the pins on the ETM itself. Do not touch the pins as these will bend and break very easily. (I can't remember if they have thin pins or not?)
Just clean them with electrical cleaner and re plug in.

Ignore P0121...it's only showing up because the ETM fault.

[LeeT5]

Well I went out to the car last night and it started, and cut out straight away. it restarted and cut out again.

P1603 - Throttle Unit Internal Fault.
P1609 - Throttle Unit Internal Fault Signal too low or missing.
P0121 - Throttle Pedal Position/Switch A Circuit Range.

However, erased the codes and started the car and it's been how it was. Still a bit odd and no EML lit or codes stored.

Laptop and vida should be here on thursday though :D

How can you say 'no codes stored'? Where did you get these from then??
You don't always get an EML light when the ETM goes bad.

[Mart5in]

In the following order:

https://dl.dropboxusercontent.com/u/4699930/volvo/Faulty%20tps1%20and%202.jpg

You can see in the first few seconds, everything appears normal. Then you can see the throttle demand staying level - since my foot was steady on the pedal. The TPS signals are all over the place.

This 100% points me to the ETM - which was converted by a mechanic friend around 3000 miles ago. Spent about 2 hours carefully scraping the sealant out. What I found was obvious.

https://dl.dropboxusercontent.com/u/4699930/volvo/cracked%20solder.png

Circled in yellow at the top of the pic, was a blob of solder on top of that which came off as I was scraping the sealer away.

In the middle of the circle at the bottom of the pic, you can see that the pin from the TPS isn't actually soldered to the ETM pin. merely sitting against it.

I re-flowed the joints with old school solder with flux core - leaded.


Conclusion: cheap solder doesn't stick and don't let your friends work on your car when he wants to "chop" you with his V70 :P definitely sabotage! hahahah


Thanks for all the help.