Greetings:

I have post this message some time ago (August 9th) since I first sign up as a new member to this forum. I have not seen any reply or feedback response to my problem in question. I assume that I must have post it in the wrong place (at the new member section perhaps?). So I am hoping this time I will be able to post these questions again in the right place so hopefully I will get some nice feedback to all those helpful 'troubleshooters' out there to guide me to resolving this problem on hand. Here is the same message that I am forwarding here to this posting.

I am hoping this Q&A Forum regarding Volvo's will resolve one of many problems of owning the 940 Volvo's.

I have three problems or situations which someone might be able to help me 'troubleshoot' before I bring in for repair (if necessary).

First, I own a 1993 Volvo 940. The car has about 112K miles. Recently I notice the "4th" gear light (according to the owner's manual) on the dashboard went on and off (once in a while) but does not stay on. I thought maybe I have accidentally touch or activate the small button on the shifter control ****. So I press it hoping to reset it back to normal. Still it comes on once in a while. Hope this is nothing major or problematic to the transmission or engine.

Secondly and recently when moving the shifter from 'Park' to 'Drive' or back and forth, I notice a funny noise (slight grinding type) when shifting. Normally it is smooth when I move to the shifter position in any of the gears. Can this coincide with the first incidence or problem?

Lastly, I am currently experiencing the car is 'shutting down' when I am in the middle of driving. It happens from 5 to 10 minutes of driving. The car simply 'dies' as if there was no gas in the car when I depress the gas pedal. It has happen a couple of times with no symptoms except all the dashboard light comes on. I quickly place the car in neutral and pull over and stop the car. I re-start the ignition (sometime once or couple of times) and once it was running, the car drives normally for the rest of the trip. What is your prognosis or status regarding this problem? Any relationship or correlation to the other two problems? Appreciate your diagnostic approach or suggestion for me to check. THANKS AND HOPE TO GET SOME FEEDBACK THIS TIME AROUND.

 

It could be many things. Like a fuel pump relay,power stage,fuel pump.

You need to have someone look at it and see if you loose fuel or ignition when it happens.

 

Thanks Tech for your proper response.

I just want to be more clear on your suggestion. What should be the best approach or diagnostic to check first or to start with? I do not know what you meant by 'loose' fuel or ignition. Do you mean the lines (fuel) and cables (ignition)? Also from the other posting forum, I notice similar question and problems like mine. As I read through most of them, I was confused on the many different types of prognosis. Anyway, can you direct me to where these items are located on the vehicle or what it should look like so I can visually check and perhaps change the parts one step at a time (least expense parts first in terms of labor and cost) to see if it resolve this intermitten 'shut down' problem. I assume the first thing would be the fuel pump relay supposely located in the relay box. I also notice from the other post, possibly the noise (radio) suppressor relay as well. Also mention was some sort of ECU and "144" code which I don't know if this is mention or pertasins to my case. As stated, the only thing when the car 'quits' (with no hesitation or stuttering or noise) is the dashboard comes on with the usual diagnostic lights. If is, what is this ECU or location or what am I looking for if applicable? Next, what is the power stage? What should I be looking at in terms of viewing and checking since I am not familiar with this part or location? Is there a specification or illustration of this (like Chilton's repair manual) that I can get a better feel on the car's engine compartment? Finally, the fuel pump, is it the external or internal pump and where should I start to check? The only thing is that I do not hear any unusual noise coming from the fuel pump when the engine is running. Any other suggestion will help me to attempt a 'step-by-step' check and hoping I can find the culprit to this 'unsafe' condtion everytime I take the car on the road.

By the way, was anything mention regarding the funny (unsmooth/slight rubbing or girinding) shifting noise when I am shifting gears (from 'Park' to 'Drive' and vice versa). It use to be very smooth in shifting. Perhaps it need to be lubicated somehow or sign of trnasmission problem since I didn't notice and unusual change when engaging gears. Thanks again and hope to hear from your professional response.

Also, do you know how I can find out what the numbering on the automatic transmission or where the number is located? I need to find out the correct designation numbers (starting with AW# for correct ordering and usage purpose) to purchase the correct transmission filter kit for my 1993 Volvo 940.

 

I would start with the fuel pump relay located in the dash at the relay panel.It is a big white relay.
Also if you have 2 noise suppresion relays under the hood by the coolant bottle swap them around and see if the problem still happens.

The power stage is located on the inside of the left side fender.It is a black sensor mounted on a peice of aluminum.The alumimun bracket is what bolts to the car.

Sorry I meant to see if you lose fuel pressure not Loose fuel pressure.

Try this site to try to learn how to pull codes.

http://www.troublecodes.net/Volvo/

The fuel pump is internal on your car.

For the shifter problem it might be the shifter bushings.They wear out and fall apart.

Your transmission should be a AW-70 look on the left side of the trans itself and you should see a plate that will tell you which you have.

 

Thanks Tech

Just a few other questions to address. I am waiting for the fuel pump relay (on order) to be check on or possibly replace. If this doe not resolve the problem then I will check the noise suppression relay as you stated.
I have a problem to get access to the relay box by the fuse box beneath the radio. First the shift lever is in the way and I can barely access the front fuse section while the relays are mounted on the back of the fuse box area. The only way I can do is turn the engine on and move the shifter in 'neutral' so I can at least have some space or room to pull out the fuse box while trying to access the back of the relay box. Still I have a hard time to get access or room to 'pull' the complete unit out. Do I unclip the side (looks like retaining clip that is securing the box in place) and just pull the entire unit (relays & fuses) out (since I am not able to pull out the individual relay from inside)? There must be a better way to be more accessible to the fuses and relays.
I assume I have only 'one' noise suppression relay instead of two (since I cannot find any other relay or similar one nearby the coolant bottle) but am not really sure is this is noise suppression relay that I am looking at to begin with. From the make of it, is this the relay that is located next (mount on the side) to the ABS unit and the Fuel Injector unit? Maybe my car has one while others of the same make and model have two. I see part number 899931 on it. If I have one then I cannot swap them around to check if it is faulty other than to replace it with a new one and then see if the problem is resolve. Any suggestion or test I can do other than buying a new relay to perform this trial and error?
I assume once I verify that it is not the fuse relay or the noise suppression relay, then the next thing to check is the "power stage". You stated it is the sensor enclosed by an aluminum bracket which is also mounted on the left side (driver) fender next to the power steering & strut mount tower. I see a 3 wire prong (green) plug attach to it. What do I need to check or diagnose on this sensor or simply replace with a new one? Also according to the description, the 'power stage' as stated in Chilton's manual is part of the Ignition coil that is mounted or attach together and this sensor is mention as a 'pressure' sensor. I am a liitle confuse by either the description, functionality or actual part location. The bottom line is as long as the description of the part match with the proximity or location of where it should be would be the main part to check.
Also from what I am able to read up and try to determine is what type of 'Fuel Injection' system I have in my car? I am confuse with what makes up my 'fuel' system and 'ignition' setup on my '1993' 940. First I have verify that my ignition coil (Siemen) is hooked up to the distributor (Bosch) located on the back end of the engine next to the firewall. The coil lead wire is attach with a special clip on the coil side. This ignition coil is also built or attach to the 'power stage' (also call 'Ignition amplifier' as illustrated on Chilton's) which leads me to conclude that it is a Regina/Rex ignition system. Since the ignition coil is not a Bosch type, I assume this is a non-Bosch Fuel Injection system or Regina/Rex F.I. system. But the Fuel Injector box (next to the ABS) is a "Bosch". So what type of system is it that uses the Regina coil hookup hook up to the Bosch distributor cap (expensive flat mount type not the typical cheap round type)? Can it be a combination of a Bosch F.I. system with Regina ignition system? I thought it is either "Bosch" or "Regina" base on the year, make and model. Note: I also own a '1994' 940 which have a 'Bosch' coil ignition located on the right side near the strut tower (instead of the 'Siemen' coil/power stage) without the sensor (power stage as you call it here) with some differences in parts and hookup configuration. I assume this looks like a "Bosch' F.I. and Ignition systems.
One final note regarding the fuel pump. According to the type of system, it mention both an 'in-tank' (internal) fuel pump & 'external' (pre-pump) on one illustration and yet another schematic shows only an 'internal' pump for the same system. They also stated that the internal pump (one only) is a two stage type pump to replace the two pumps type. This can be very confusing! Let me know what you guys have to say about this. Any information or feedback within this forum can be an asset to troubleshooting your Volvo's. Thanks again.

 

Did you take the cubby out from under the radio?

If you have a square coil you have Regina Rex I believe the power stage is part of the coil on the regina rex.

You can tell if you have 1 or 2 fuel pumps by looking under the car on the drivers side and see if there is one next to the fuel filter.
I beleive you only have one.

hope this helps.

 

Thanks Tech

Just a quick response to your answer.

I did not realize that I have to remove or take out the 'box' compartment beneath the radio to get full acesss to the fuse/relay box. Normally I just reach in with jsut enough clearance to check or replace the fuse but not realizing that the relays reside far back behind the fuse section. Thanks for your suggestion.

Any diagnostic procedure to check on the noise suppression relay or simply replace? Is this the (only one) relay adjacent to the ABS & Fuel Injector unit?

Since I have the square coil type mounted (as part of) with the 'power stage', should I be checking on 'this' part of the 'power stage' or check what you thought was the 'sensor' that is mounted separately (enclosed with aluminum bracket bolted near the left side fender with green plug - 3 prong attached) as previously suggested? What part(s) needs to be check or to perform any diagnostic procedure (or possibly replace) here before moving on further in my trouble-shooting process? Note: Chilton mention this 'sensor' as a "pressure sensor" which exist on the Regina Fuel system.

If after diagnosing or replacing all the possible relays (fuel pump, noise suppression, power stage perhaps, pressure sensor), I assume the the last to check would be the fuel pump itself. Do I need to check for fuel pressure first since the pump is working? How do I check and maintain what proper pressure requirement before replacing the fuel pump?

Base on the type of ignition coil recognized (Regina/Rex) on this year and make, I assume that it has a Regina 'Ignition' system but with a Bosch F.I. system setup (since it has a Bosch injector box) even though Chilton's only mention them as separate complete (Regina or Bosch Ignition & F.I.) systems. A 'hybrid' fuel & ignition system perhaps?

How easy is it to replace the shifter bushings and what needs to be taken apart? Anything else needs to be check as well or possible replacement?

Thanks again and again.

 

You can try to replace but also make sure it is for the fuel system.Try to get the electric cooling fan to come on.Then unplug the relay and see if the fan goes off or the car stalls.


Im not sure about the power stage I will try to get a picture and post to make sure we are talking about the same thing.


You will need to try to find the fuel guage setuo that will fit on the car.Then you will need to monitor the pressures.


Regina is supposed to be the ignition system and Rex is the fuel system.
When you try pulling codes you will need to pull from the fuel system and the ignition system.


The shifter bushings are easy to replace.You will just need to remove the rod under the car from the shifter to the trans.The bushings go in the trans arm and the shifter arm.I think you also have one that they call the top hat.It goes on the transmission where a rod goes towards the top.