crank, no start.

[thejallenator]

.

ECM-903F (P1608) Throttle position (TP).

Signal missing
When it comes to the comparison between desired throttle angle and current throttle angle, the Engine control module (ECM) must have received the current throttle angle from the Electronic throttle module (ETM) on the CAN-net, before the test is activated. The deviation between desired throttle angle and actual throttle angle is changed from the fixed value of 5 %, across the whole range, to a variable limit. The variable limit is within 5 % deviation at 10 % desired throttle angle, it is then increased up to 10 % deviation at 50 % desired throttle angle. In order for it to be considered a deviation, is requires that the current throttle angle is greater than the desired throttle angle, which is a difference from before. Then the diagnostic trouble code was also generated if the desired throttle angle was greater than the current throttle angle.

Closing of throttle during braking.
The accelerator pedal position is ignored when the brake pedal is depressed.


Possible source
Signal too low or signal missing:

• Low voltage feed to electronic throttle module (loose connections or contact resistance in connections, low system voltage).
  Damaged CAN cables.
  Disruptions on CAN signal cables.
  Damaged electronic throttle module (ETM).

Fault symptoms

• the accelerator pedal (AP) is ignored when braking
  the cruise control is not functioning at all
  uneven idle
  jerks during engine braking.

first off, just want to clarify that the CAN signal cable is essentially the engine wiring harness?
im almost certain that if this is the case then i have a bad harness, i remember for the longest time i would see a signal missing code for all 5 coils at one point in time on vida. never got it figured out, always was present regardless of what set of coils i usesd, new and old ones. could explain the full boost level the car "sees" at start up.

any way to rule out one thing or another. i noticed that the values present for either side of the ETM were fairly close when moving the throttle pedal. and i have a brand new battery. possible connection issue maybe. after the ETM plugs into the harness where is the other end of the harness? in the box thing next to the power steering pump? if so how sealed is this? car had a bad PS fluid leak when i hgot it and everythig was covered in fluid.

[RickHaleParker]

The first thing I would do is check the cable connections, make sure nothing got knocked around when working on it. Then have a dealer check the software versions. That why I would know if I have the correct software for the hardware and configuration.

Controller Area Network (CAN bus) is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other in applications without a host computer. It is a message-based protocol, designed originally for multiplex electrical wiring within automobiles to save on copper, but is also used in many other contexts.

A easy way to tell the CAN-Bus cables from the power cables is, the CAN-Bus cables are twisted pairs. CAN-Bus cables are routed along the wiring harness with the power cables.

[thejallenator]

A little googling and I'm still partially confused about the canbus, but have a general idea. I do see something about the radio being involved with this in one way or another and when all the problems really started and the car left me stranded for the first time when I finally got the car started again the LCD display on the radio never worked. It lit up and still displayed stuff but didnt read correctly. Like everything would light up or it would. Scroll the radio channel numbers across the display ei 92.7 read 9999999999222277777 or something. Now it reads nothinf but the backlight is on. Not sure if this has anything to do with it. Shooting in the dark now. how Can I go about testing the canbus system? I cant let this car beat me!

[abscate]

The communication here is between the ECM and ETM only. Check all those connectors by removing and cleaning them with contact cleaner, the next step after that is probably ETM replacement. I think you have the last of the MM ETM which go about 150k miles before dying.

I found a decent website on for CAN tools at picoauto in the UK, but this is over the head of most if us here. The tools exceed the value of most of my cars.

[thejallenator]

Most of the info I gathered from the internet about the CANbus stuff was definitely over my head and not something I want to mess with. As far as etm goes, this is at least the second one for the car. Something like a date ot may 05 I think. It has the yellow sticker. Going to check all the connections this week and go from there. A buddy is coming by this weekend with a 2001 v70xc also. Can I pull my etm off and test it on his carwith vida/dice, hoping he has had the software update? Both are tbe same year, I think I've read something like this about a guy just plugging in etm's to his car to test them.

As far As replacing it, I see these "refurbished" etm's coming out of China. They look pretty dang new, bur its just a stock photo. Not the actually unit. Curious if anyone has used these. Seems better than a used one off eBay. Pretty hit and miss there you'd think. If like to just replace the tps in my unit but in would also like to have a second unit in case I ruin on taking it apart.


Taking the car to a dealer is not realistic. Car is too unpredictable to attempt the 180 mole round trip to a volvo dealer.

[abscate]

A refurbished unit from China with a stock picture? You might find a stick in your eye more useful

The difference between the yellow and white label ETM is the color of the sticker.

There is roughly a 20% chance a swapped ETM will work in a different car. Not good odds.

People on eBay haul them junkers, spray them clean, and call them refurbished. It takes 2-3 hours to check and fix the wear parts so if it's $50 part, you are buying a junkyardpart not a " refurbished part"

You've got to plan on spending $500-700 to deal with an ETM between hardware and software. It's the price you pay for not having to deal with all the pre 1998 tune up stuff.

Once you do that it last 100k miles

[thejallenator]

Chinese unit

https://rover.ebay.com/rover/0/0/0?mpre ... 2312779032

Looks pretty odd. Can't send the seller a message or anythint. Definitely not Gunna go with one of these.

I'm already in kinda deep with this car. Buying a xemodex unit would be nice. But not sure how practical it is to spend that money for me. I think I might actually just buy a second unit and attempt to rebuild it myself. Looked into it a littlw bit. Doesnt look too complex.

[RickHaleParker]

The $129.20 is for hardware only. It will still need to be cloned from your current ETM. XeMODeX charges $250 to clone. Your still looking at $380.

[thejallenator]

The $129.20 is for hardware only. It will still need to be cloned from your current ETM. XeMODeX charges $250 to clone. Your still looking at $380.

Dann, volvo really burned people here. So I couldnt just rebuild my existing unit with the new tps and just plug it in? But I can take a used one and plug it in no issues? Its tough to attempt to buy something that is roughly 25% of the cars value. Not to mention what ive put in already. Seems like a nice money out :/ I want it fixed but damn.

I should be able to plug my etm into a friends car to test it correct?

[abscate]

Fixing a car isnt relevant to its value at this point

If you drive the average 12,000 miles per year, the cost of ownership without capital cost is something like 3000-4000 per year depending on locale. The capital cost on a newer one will swamp that, its always cheaper to fix and old one if its in decent shape.