Where do you reside? Just general is fine. State, province, region, continent, nation, blah, blah. Humid, or snow and salt, or seaside damp, can all cause problems to the electrics.

Yet at 27 years, a 1989 Volvo 240, even in dry, dry, dry Arizona may form corrosion at any bonded electrical contact such as the fuse box fuses, wire harness termination spade or ring term, ground connection, or wire harness connector.

No Hall-Effect sensor in the distributor in your 1990 240. A different ignition timing method, that checks the crank position, through the CPS, on your version of the Bosch EZK (I forget the number - 116?)

You say your already replaced the fuel injection relay here:
https://www.brickboard.com/RWD/index.htm?id=1634675&show_all=1

On that same thread, you reply to Dan (Pageda) Sat Jul 9 12:26 CST 2016:

pageda - I get a code 224 on pin 6 stored currently in memory. The temp guage has worked sporadically but mostly doesn't work. It typically lays at the bottom showing cold. It will come on sometimes and seem to hold steady or sometimes rise to high. A year ago when I checked codes I got the same 224 on pin 6 (should have done something I'm sure) and on pin 2 I got 113, 123 and 232. Thx so much. Mark

Also, here, you indicate problems with loose fuses in the fuse box:
https://www.brickboard.com/RWD/index.htm?id=1630792&show_all=1

So, begs the questions .... did you check the condition of, or replace, or is already replaced, the single ATC fuse and the ATC fuse holder behind the battery and in front of the North American driver side front inner fender strut tower. By now, the factory ATC fuse holder would have deteriorated so much so it may be unsafe.



Please see Art's page here:
http://cleanflametrap.com/emfuse.html

Corrosion forms at the fuse contacts and where the wire harness terminates at the spade terminals at the backside of the fuse box. (Requiring removal after you disconnect the battery.) A quick wiggle can dislodge a corroded connection. 27-year old spade terms at the wire ends can break.

Clearing codes as many suggest does not make the fault to cause the fault code being set at either ECU to go away. Though faults begin intermittently, that can effect performance and emissions, by the time the forgiving Bosch engine control on your 1989 Volvo 240 reports the fault, it is a fault requiring attention.

You have used the OBD to check for fault codes. Socket 2 is fuel injection and emissions. Socket 6 is ignition and emissions. So, in two unique threads, you mention:

Your reply to Pageda, Sat Jul 9 12:26 CST 2016:
Socket 2 - fuel injection and emissions
113 Fuel trim (lambda control) too lean or rich - detected at 02 sensor
123 (fault in signal for coolant temp sensor)
232 (battery voltage high or low)

Socket 6 - ignition and emissions
224 (coolant temp sensor is faulty)


The codes you report in this thread, Sun Aug 14 19:38 CST 2016:
Socket 2 - fuel injection and emissions
123 (fault in signal for coolant temp sensor)
132 (battery voltage high or low)


Socket 6 - ignition and emissions
224 (coolant temp sensor is faulty)

So, to remedy:

#1
Socket 2 - fuel injection and emissions
232 (battery voltage high or low)

Do you have a multimeter to check voltage at the battery before starting the engine. With the dash idiot lights on. And then check the voltage after the engine starts.

A cold alternator produces around well, 13.8 to 14.5 volts DC. As the alternator warms, the voltage drops to around 12.5 VDC.

If you can start it.

If battery has a good charge with all off, key not in the ignition switch, as checked by your multimeter set to check DC volts.

A high / low charge can mean fault in the alternator wiring (check the ground wire on ring terms between the back of the alternator and to the engine block), or a charging fault at the alternator (voltage regulator brush carrier to high / to low), or internal alternator failure (a field coil winding). You do not complain of dash lots remaining on after engine start, however.

#2
Socket 2 - fuel injection and emissions
123 (fault in signal for coolant temp sensor)

Socket 6 - ignition and emissions
224 (coolant temp sensor is faulty)

Both engine control units use the same part of the wiring harness between the ECT to the wire harness.

One of two causes ...

The sensor is faulty or its installation is faulty. If the engine coolant (antifreeze + distilled, demineralized, or deionized water [NEVER tap water]) is old, the ECT sensor can fail. You may have corrosion between the sensor thread and the thread in the aluminum alloy cylinder head.

Or, the wiring. Fault can form at the ECT connector if dislodged or dirty or corroded. The wire from the ECT routes inside the harness where the wiring for the four fuel injectors split. There is a crimped (not soldered!) connection that can also corrode causing conductivity problems between the ECT and the two ECUs. You can feel this crimp as you grasp the wire harness between intake manifold port runner #2 & #3 as a slight bulge. With your multimeter, you would check for continuity. You may haver to get to the ECT connector and verify the wire harness end to end.

#3
Socket 2 - fuel injection and emissions
113 Fuel trim (lambda control) too lean or rich - detected at 02 sensor

A fault at the ECT will cause a fault in the ability of the both ECUs to control fuel trim. So, check and mend the ECT and other faulty electrics first.

Also, do you have a service manual? The very best for you may be:


https://www.amazon.com/Volvo-240-Service-Manual-1983/dp/0837616263


Follow the other posters suggestion, yet always best to resolve the cause before throwing $$$ parts $$$ at it as a solution.

Do not believe the myth of the indestructible Volvo 240. Any 27 year old automobile will require vigilant, anticipative care if you want it to continue to operate reliable and safely with good performance and clean emissions.

I'll bet your brake fluid is black, huh?

Sorry to be so grim-sounding. Unemployed, again, in stinky st. louis mo, the fascist crap hole. Well, all AmeriIKa is a fascist crap hole, for me.

Questions?

Hope that helps.

MacDuffy's Monday Mourning Tavern.
--
Give your brickboard.com a big thumbs up! Way up! - Roger Ebert.