All,

As you remember last week I posted about my 16 yr old son being involved in a 3 car accident caused by a drunk, and how he put the car (95 850 Turbo sedan) in the ditch to avoid a collision. As you remember, the car suffered no damage and drove like a dream after being pulled out of the ditch.

Well, today the car got sick on us. Here is the story, and I could really use some help figuring this one out.

The boy was driving the car home from school today (15 mile trip on the highway)and he said the cruise control kept kicking itself off and when he would take his foot off the gas, the car would keep gradually accelerating. I thought it might be asticky throttle cable, so when he got it home, I used WD-40 on the throttle cable and surrounding mechanism. I worked the throttle a few times (with the car off) and it seemed fine. I then pulled off the MAF connector and found some light corrosion, so I cleaned the pins and applied a dab of WD-40 to them and re-assembled the connector. Then I tried starting the car and it would not start! I tired 7-8 times and no start. Cranks fine, but no fire. I then smelled raw gas so I figured it was flooded. Fast forward to 2 hours later. I went to try starting it and as soon as I turned the ignition to "ON" (position II) but not "START" both the engine cooling fans started running! Weird, but I tried starting it anyway. After 3 tries it coughed, sputtered, andfired,belching a ton of black smoke (from being flooded I'm sure), but then setteled into a fairly smooth idle. I then noticed the check engine light was on.
I shut it off and the cooling fans kept running. I checked the codes and only socket A2 had a code...which was 1-2-3. I tried clearing it 4 times, and it would not clear, so Idefinitely have a hard 1-2-3 code, and this is the only code. Now for the really weird part. The cooling fans will now run constantly with the ignition off completely and the key removed. The only way I found to get them to shut off is to open the plastic computer module box, and remove and re-insert the module nearest the drivers side when facing the motor (I believe it is labeled B2)

SO in a nutshell, the cars starts, but has a check engine light and a hard 1-2-3 code, and the cooling fans will keep running after you shut it off unless you remove and re-install the computer module.

Looking on this site, I see that code 1-2-3 points to a faulty throttle position sensor signal, but on another site, it states code 1-2-3 is caused by a faulty coolant temp sensor signal. Both code explanations seem to fit the problem.

Help!!

Glenn

 

According to http://volvospeed.com/Repair/a2.html the 1-2-3 is a missing ECT (Electronic Coolant Temp) sensor code. If that's the problem, the ECT sensor is pretty easy to replace. It's located right under the t-stat.

Edit: More info.
http://volvospeed.com/DTC/a2_123.php

 

Thanks RedTurbo850, I'll definitely check it out. Looks pretty easy to change the sensor too. Do you know if there is a way to check the sensor with an Ohm meter to see if it is definitely bad and not the associated wiring that is causing the trouble?

Glenn

 

Not a clue. I think JPN would probably know....

Although...I think I did read JPN's response to this once. If I remember right, you put the sensor in a pot of boiling water, and then read the ohms (correspond to various temps).

It's a 20 or so dollar part. Not worth the time/effort imo. I believe the replacement will also come w/ the wires (they extend off of it).

Edit: Did your son see any erratic movement of the temp gauge at all?

 

Thanks,

I'm just going to go ahead and order the part. It is only about $30 from Groton, and I have to get some oil filters anyway. I asked my son and he said before he shut it off yeaterday, the gauge read really low, and that was after running at 60 MPH for about 20 minutes. Sounds like a bad sensor to me!

Glenn

 

Hi Glenn,

Sorry for delayed reply, the time is completely the opposite in Japan and I've been having such a nightmare at Narita Airport in Japan (dealing with people in this country[8D]).

Anyway, since you've ordered the ECT sensor, I won't get into the testing procedure.

I have a feeling that WD-40 you have used may have caused short-circuit within the MAF sensor connector. WD-40 is conductive, and if not wiped clean completely (I usually use Office Max's air duster), it can cause short-circuit. Electrical contact cleaner may have been a better choice.

As to the cooling fan, there seems to have been other models that have had same problem. I have a bad feeling about the Engine Control (Fuel Control) ECU; it may have been damagedeither from the ditching incident or short-circuit from the MAF sensor. Also, when you remove the ECU, be sure to disconnect the battery and wait at least 15 minutes for the relay to stop supplying power to the ECU. If this is not followed, the ECU can get damaged permanently.

Also, check the ignition system for proper firing. It could be anything; CPS, coil, power stage for the coil, distributor cap & rotor, ignition cable, plugs etc unless they have been done lately.

BTW, when was the last time the T-stat has been replaced?

I'll attach testing procedures/wiring diagram for CRZ & Cooling fan systems. When you're done saving them, please let me know so I can delete them. Or, if you like the same copy, you can get them in PDF format at: http://www.volvoclub.org.uk/volvo_wo...techdocs.shtml

The PDF manuals are not complete; they are missing some info. You may have to become a member at the web page to get the full version. However, I find that with this manual plus Haynes, you can solve approx 80% of the problems by yourself, as long as you have the necessary tools& equipment.

Lastly, try an AutoZone and OBD-II. If they use Actron CP9175 or better scanner, they can find out if the ECU is shot.


JPN

 

.


JPN

 

.


JPN

Since the car is exhibiting multiple electrical & electronic problems, I suspect the ECU. OBD-I should report 1-1-2 for ECU failure.

 

JPN,

He's able to pull codes from the ECU. I don't think it is dead. Regarding short circuiting the connectors with WD40, I don't think the ECU will fry. Otherwise each time there is a bad connector you would need a new ECU.

I'd better shut up before Volvo hears me and removes the overload protection on the sensor input pins.

 

That you're right,therefore the problem may actually be in the CEU (Central Electrical Unit = fuse box). Some relays could be bad? Both the cooling fans & CRZ use relay. I do suspect the ECT sensor, but I am not certain as to the coincidental malfunction with the CRZ.


JPN

 

JPN,

Thank you for the diagrams, they will be a big help. I downl;oaded them so you can remove them when you wish. I appreciate the help pointing me in the right direction. I too think the WD-40 in the connector could have caused problems. I forgot it was conductive until after I used it (duh). I am going to clean out the connector with some rubbing or denatured alcohol and blow dry to be sure I got it all clean.

Weird thing is that today, my son got a bit anxious about his car and he went out and started it while I was at work. He said it started right up and ran fine, and the check engine light was off!! Beats me, but I told him not to drive it until I get agood chance to look it over and ruin some checks. It is 500 miles shy of 180K, so it is due for an oil change, and tune up anyway, so it sounds like a good time to dig into it and get it all done at once.

As for the thermostat, I changed it when I changed the timing belt and water pump.....about a year and 10,000 miles ago.

I'll keep you posted as to what is what. The temp sensor is schedule to arrive in about 6 days. Until then, the boy can ride his bike or catch the bus <grin>

 

Hi Glenn,

I do wish you the best with your son's 850. Also, try OBD-II anyway to see if a scanner reports something that the OBD-I didn't.

My pleasure for assisting you as much as I can; you have been my mental support for many times when I had to deal with negative-minded people.

Will wait for your update, and I will delete those pics. Also, Tech is back again (with updated signature photos) so Tech may have better ideas, as usual.

Best of luck,


Kanji/JPN

 

I would wait and see what the temp sensor does.

 

Hey Tech, nice pics!

However, I kind of like it stationary, and kind of miss your Mustang.

BTW, may I suggest that you add a rear spoiler on the white 850? Let me know if you need an assistance convincing your wife[8D]. One cannot under-estimate the immense power of SUGGESTED SCENARIO[8D].


JPN

 

I have 2 of them in the garage. I have to wait for some spare $$ to have it painted then I am going to install it.

But with having to go to S.C. for the funeral the other week the $$$$ is in REAL short.

 

>the $$$$ is in REAL short.
Aren't we all.


JPN

 

+1. I have to go to Panama for three weeks to work but I have been postponing it because I don't have the cash. The customer will reimburse the travel expenses, but it is more than USD 4000.

 

Sweet Pics Tech,

I know about money being short, Seems like the story of mine and almost everyone else's life <grin>

Small update to the 850 for everyone. I messed with the car a bit this morning just for the heck of it. I cleaned out the MAF connector with rubbing alcohol and a toothbrush, and then blew it dry with an air compressor to get all the WD-40 out.

After it dried, I started the car just to see what was what so to speak. Anyway, the cooling fans came on as soon as I turned the key to "ON". The car started fine but idled a bit rough. I let it idle for about a minute and noticed that after sitting all night and only running for about a minute, the temperature gauge went right to the 3 O'clock position. Not right to say the least.

Then, for grins, I turned the A/C on to see what the car would do under load. It bogged down and idled really rough and almost stalled unles I fed it gas. It was also very sluggish to respond to the accelerator pedal when revved. Once the A/C was turned off it ran better but still revved sluggish. Same thing if you put it in gear. Rough idle and very sluggish but seemed to get better as it slowly warmed up. Cooling fans were on throughout the whole affair.

After 3 minutes, I shut it off and decided to check the OBD-I codes, and I still have a 1-2-3. I'll get an OBD-II scanner on it as soon as it stops raining. I'm thinking the bad Temp sensor is telling the ECU that the engine is running hot and causing a screwy fuel mixture making it to run rough when cold.

The son is not happy, but I told him to keep it parked until the parts arrive from FCP Groton later in the week.

Any thoughts ? Forgot to add that after about 5 minutes with the key off, the cooling fans shut off by themselves.

Glenn

 

Hi Glenn,

With the same code coming back and the cooling fans turning off after a little while, it does seem that the temp sensor has gone south. I hope the new sensor would cure all problems that your son's 850 is having.

According to the factory manual, the resistance value (Ω) keeps dropping as the coolant temp goes up, so if the sensor (most likely a thermistor) has shorted, meaning zero (0) Ohms, the sensor is sending signal to the ECU that the engine is running at max hot. This would trigger the cooling fan without the engine running, as long as the key is turned to "ON-Position-II".

If, however, the new sensor does not solve the problem, then I would suspect the relay for the cooling fans.

Will wait for your update.


JPN

 

+1 on the coolant temp sensor.