i am at college, and my volvo has been sitting for almost 2 weeks without being started. i went to warm it up tonight, and it wouldnt start. after it wouldnt turn over, i heard a clicking noise from somewheres around my radio/shift *** area. after deciding the battery was dead (it is 13 degrees out btw) i jumped it, and she started up. the drawback is that the check engine light is on, and worse off, the arrow that signals winter mode on is flashing. in my owners manual it says "if the warning lamp begins to flash, this means that there is a fault in the automatic gearbox. contact your volvo retailer." well, i then tried to drive, and soon realized that my volvo was in some sort of "limp home mode" and had trouble starting off (like it was stuck in like 3rd gear or something). it drives ok i guess once you get started, i didnt go over 35 though. even after turning her off and restarting, its still there. has this happened to anyone before? is it safe to drive the 2 hours home? please help.

 

I wonder since you had the battery die, if the transmission code was brought on by that... I would say pull the codes and have them all cleared. Go from there. It's hard to diagnose a car, sight unseen and also without codes. Good Luck, we will try and help as much as we can with the info provided, but we need a little more info...

 

well, i limped over to oreilleys to use their OBDII scanner but they were already closed. i am going tomorrow first thing. will know codes then

 

Cool.... Post them as soon as you get a chance!

 

been searching around and found this:

Anytime you get the flashing arrow you will get a CEL - I guess they just wanted to add urgency to the issue when they wrote the firmware for the ECU and TCU.

9 times out of 10 it is a PNP switch problem at least with my 850s. On the 850s I can read the transmission codes just fine with a standard OBD-II scanner, on the later models that may be different. I will defer to JRL since he has much more knowledge on the later model cars than I but I thought that federal law required that any power train (P) code be readable via an standard OBD-II scanner.

Once the flashing arrow sequence is initiated it has usually gone into "limp home" mode which means that the car is basically stuck in 3rd gear. Anything beyond "limping home" is really tough on the transmission internals. A series of short trips shouldn't kill you but limit driving as much as possible until the problem is dealt with.

describes what is happening to my car perfectly. what is a PNP switch?

 

PNP stands for Park/Neutral/Park. It is the switch that requires you to engage the brake before shifting out of P (Park) into gear. It is a safety mechanism.

 

where is this switch located?

After dropping $100 on a new battery this morning in 19 degree weather, i managed to get her started and limped over to oreilleys. pulled the codes:

P1618 check engine code
P0605 internal control module read only memory(ROM) error (module identification defined as SAEJ1979)

does that mean that i have to take it to Volvo to have it read?

 

P1618 is a manufacturer- specific code, which the generic OBD-II machines don't read. That code is "cable fault between transmission control module and engine control module. The cause of this is an open or short between the wire that connects the TCM to the ECM.

The second code is an internal memory error in the ECM. The problems could be related... did you by any chance accidentally reverse the jumper cables at first? or short them together?

Here is what I would do: check the ECM and TCM wiring for any damage, especially at the connections to the ECM and TCM. Unplug the ECM and the TCM, and make sure that they seat correctly when you plug them in. then, go back to the parts store and have them erase the codes. See if the lights/ codes come back. If they do, post that in here.
You may end up needing to seek professional help on this one. It's also possible that something has fried the ECM, and it may need to be replaced.

 

Oh, and the PNP switch, unfortunately, won't cause those codes. Wish it were that easy.

 

ok, i dont think that anything happened with the jumper cables. i didnt notice if it did. ok, i know that the TCM is located right under the air box. where is the ECM located?

 

I would try disconnecting the battery waiting 30 secs. to a minute and reconnecting. Try to connect so you don't have any arcing. The microcontrollers in the ECU and TCU have to go through an intitialization sequence before they start to run the firmware main program loop. If this intitialization got interrupted and skipped a step, like the flash controller setup, this could cause a problem with reads and writes to flash(ROM).

There are most likely safeguards for this in the firmware but you never know. anyway it's easy enough to try it.

This process however will not erase the ROM error code that is already in flash so you might have to take it somewhere to get the code erased.

 

well, i let the battery sit unhooked over night. didnt change anything. taking her to volvo tomorrow. will let you guys know how it turns out

 

TCM is right next to ECM, in the same box

 

I would try to get the codes cleared and see what happens first. I had that arrow flashing on my 850 R a few weeks ago, cleared the code and everything has been fine since.

 

Oh yea, before I forget... Try not to let an old car sit for longer than a day without a short drive. For some reason, they don't like it. My 960 was popping codes when my wife was driving it once per week. I've been taking it out daily or every other day and it's running great with no codes. The same happens with my 850 R. When it sits for a week or more, I get codes. Drive it every other day and nothing.

 

The reason for this is that the microcontollers in the older cars ECU's and TCU's used more power in sleep mode that they do today. Why? because of the PDA and cell phone revolution where small compact battery power was paramount to product success. These chips have moved into every market because they are produced in huge quantities(lowering cost) and the cost make them appealing to every industry. Nano amps in sleep mode now instead of micro amps back then. Makes a big difference.

 

thank you very much guys. took it to the dealer, they ran diagnostics and reset the computer and all codes and didnt fix it. looking like there is a short in the TCM. my plan is to buy a TCM used off Ebay, and take it to volvo to have them program it to my car. that sound right?

 

I guess you gotta do what you have to. That should help you get it back to 100%. Sorry to hear you had the problem. Try tapping it with the handle of a screwdriver. Sometimes that helps (more for stuck switches, probably not for a short).

 

If you want, you can send it to me. I've never taken one apart before but I'd like to see whats inside (I'll post photos and a description of the major components). I can examine the board to see if there are any obvious signs of shorts or burnt components and see if there is a way to fix it. If it's anything to do with the processor or firmware all bets are off. Send PM if your interested. I'll do it for nothing, you pay shipping.

 

well, volvo finally called me back today and reported a faulty transmission control module, and wants 700 bucks for that. also reported that i have an issue with my climate control and need a new blower. ($550) but i didnt have any issues with my climate control before i took it in. wonder if they didnt mess it up when trying to track down other electronic issues? also i have found used TCM's on ebay. think i can use one of those? will i have to have volvo program it? thanks.