My 1990 volvo 245 has always run pretty good, no engine lights on for 2 years. Resently, my engine light is coming on and diognostic codes 2-3-2(fuel system compensating for lean/rich mixture at idle),2-1-2(o2 sensor signal missing or faulty), and 3-1-1(vehicle speed signal missing) registering.The car idles fine, drives fine with minimal slight miss at idle. O2 sensor checked .6, and i'm not sure where to go from there. Thanks for any help!
Chuck

A rich or lean condition code is a catch all code. That means it could be many things or just one.

First having a weak ignition system can cause misfires. Bingo rich and then lean.
You say you have a slight miss.... How long since you cleaned the terminals of the distributor? Change wires or plugs? What brands are both?

.6 volt sounds normal for the sensor but you should see it varying up and down a few tenths all the time. If not, it may have become LAZY on responses.
If you have miss fires it might just be smutted up!

The missing speed signal could be from a bad connection terminal on the back of the speedometer.

The ECU gets it from there or the circuit there. The ECU uses that signal in the program to do various things emission wise. If the car has an EGR it will know if the car is idling or going down a grade with the throttle closed.
If you have a delayed responding EGR (leaky) that might cause a slight miss. Back to the catch all code! Usually if its bad enough it will trip its own code and light by itself.

Having the light on is saying it has an emission problem but you have to go down a chain list of combustion order to scratch off one by one. Firing of the plugs being first!


Past that,it might fix itself by burning cleaner!

Good luck and ask questions because we have all had that dreaded CEL !
I got a car for a nice price because of the valve on the fender, that hooks to the EGR, failed to turn it on! They got tired of throwing money, through an independent shop, at the CEL !

Phil

Thanks a million, Machine Man!! I did put in new Bosch copper super plus wwr7dc plugs, cap, and rotor. I also found 2 loose nuts at manifold to take-down pipe! I'm thinking that gave O2 sensor a lean mix reading, is reading between .40 and .55 now, and fingers crossed, no CEL! Drives much smoother now.I also have no EGR to worry about.Now my only code is 3-1-1 ( missing speed signal).Thanks again for all your help!

3-1-1, is your speedometer working?
Dan

Yes it is... perfectly!Thats what puzzles me with the 3-1-1 code.

I was getting a 3-1-1 code on my '90 240. My speedo and odometer both worked so I know I had a signal to the instrument cluster. I traced down the wiring and found that the speed signal that goes to the ECU comes out of the Taxi output of the ITT 2115 chip on the speedo circuit board. THis same signal is fed to the cruise control unit via the yellow wire connected to the double spade connector on the back of the instrument cluster.

In my case, we had inadvertently connected the red/white tach wire to this double spade while reinstalling the cluster one time. This apparentl fried the taxi output of the 2115 chip. Replacing the 2115 chip got rid of my 3-1-1 code and fixed my cruise control issues as well.

jstraw...Thanks so much for the info, that's what happened to me also! My odometer is not working, but speedo is. They both were working before the wiring miss-hap.I have taken my speedo apart before, and am familliar with it, but don't know where the taxi output of the ITT 2115 chip is. Any way you could give me a little more info on where it might be, and how to get ahold of a new one? Thanks again!
Panelmon

Yes it is. My odometer is not, and is not because of a bad gear!I did check the connection at back of speedo. and it tight and clean.
chuck

Ron J is right on target with his post,

You might have a bad solder joint in the speedometer head. Most likely to the stepper motor that drives the odometer.

If you go to Art Bienstein's web sight cleanflametrap.com. I think he has great directions on repairing that problem, if its part of the code problem.

I suggest reflowing ALL the solder connections that you can do in any case. Especially the wiring harness connection on the board.

The specifications Ron mentions is the sensors total range of operation extremes. You will most likely never see that on a meter as their responsing sample times may not be fast enough to display it.

I have a special sensor tester made by Actron and it does not all ways hits the limits and it has a visual LED displays. It even has two that average the readings. Flashing only one of ten single LEDS are faster than making each segmented numeral separately up and down the scale.

The most important thing to take from both our statements is that you see the sensor fluctuations in a mid range area.

Good luck at retracing.

Phil

Panelmon,

Per Volvo green manual:

DTC 311

If the engine speed is over 2100 rpm, the load signal is in the part-load range and the control module does not receive a signal from the speedometer for 8 seconds the DTC is logged.

Causes of fault:

Break or grounding in the wiring from the combination instrument.

Break or grounding in the wiring between the combination instrument and the sensor.

Fault symptoms:

Idling problems.

Also the oxygen sensor should oscillate between .1 and .9v fairly quickly.

Hope this helps,

Ron J

Have a quick read of my post.
http://www.brickboard.com/RWD/volvo/1575867/940/960/980/V90/S90/fault_code_212_oxygen_sensor_caused_fuse.html

Pull the lambda fuse out and put it back in, clear codes and see if the light comes back on.

Thanks, volvo426... I did pull a 25amp fuse I found near the battery... don't know if it was the lambda fuse. It didn't help, and still got CEL. Did do better after new plugs, cap, rotor, and tightening loose manifold to take-down pipe bolts! Fingers crossed...no CEL!

I think the Lambda fuse is in the wiring just below the hood hinge on the passenger side (LHD). Had a glitch last weekend on my 92 and my experienced passenger pulled that along with getting code 1-2-1.Cleared the code and unhitched the battery while we had a beer. Yes overkill but back to normal and no codes afterwards. 120 smooth miles since then with no problems.