Fault code question

Hi Tim,

We too have a '93 240 wagon (Classic edition). Had it since new. I would first re-clean the AMM plug's pins and sockets *thoroughly* with electrical contact cleaner, then apply dielectric grease and push and pull the plug in and out ten times. ( If that seems a little weird do it anyway. I got that from a Volvo technician .......)

You don't mention any drivability problems with the engine.

My info on Diagnostic Code 3-2-2 for the 240 LH2.4 Fuel Injection confirms your "AMM burn-off signal fault", but the report (from brickboard.com) adds that the cause is "a wiring break between FI terminal 8 and AMM #4". (I feel that could still mean the AMM plug needs cleaning.) The report also states that the symptoms are "various driving problems due to the dirty AMM wire", and the Check Engine light does not come on for this fault

Re the 1-1-3 code, the Check Engine light does come on, and the fault is "Fuel Trim (Lambda control) too lean OR RICH". The cause is "mixture incorrect (duh!........); O2S wiring fault." The symptom is "high fuel consumption".

Hope this is of some help. Good Luck. Andy I.

The 322 code does NOT set the check engine light. Something else caused it to come on the first time and the mechanic either missed it or did not pull enough codes. The no charge option could be an easy way to get you back because he MAY know what is going on but can make more money on a new AMM than fixing what is really wrong. ( Note: the last statement is from an individual who treats everything as the sky is falling and everybody is out to get me before the whole story has evolved.)

The 113 does set the check light. But, before spending any money, clean the contacts to the AMM like Andy indicates...not too much effort and will do a lot of good and no harm unless you break or bend something. See, the sky is falling...:>)

AND then...there are two ten mm bolts with wires under them on the intake manifold. Loosen them, clean them and retighten them. Also, clean the battery terminals and be sure the wires to them are clean and tight.

Then clear your codes. If any codes return after the above cleaning, then you should be concerned.

Those two bolts and wires provide ground for all the fuel control components and are also the reference ground point for the Fuel Control Computer (ECU) to "self diagnose" and set codes if something is wrong.

The manifold is aluminium, the wire's washer is some coated brass metal, and the bolt is treated steel. Combine those three differences with electricity and corrosion will occur if the connection is not tight all the time. With the different metals, cold and heat extremes ( winter driving in a nutshell) will loosen the contact enough to cause problems over time.

Every Vovlo Green Factory Service manual relating to fuel and emission issues begins with a bold statement to Clean and verify grounds and eliminate vacuum leaks prior to any testing of components.

Duane

PS. The time to clean those is just after a drive long enough to heat things up under the hood. The residual heat helps keep your fingers warm in the cold weather.

The mechanic cleaned the contacts. No dialectric grease, though. I checked the contacts visually today and they looked OK, but you really can't see into the female plug on the wire.

It runs fine so far. There is a problem with surging idle when cold, but this has been present since she bought the car 2 1/4 years ago. Replacing the fuel pressure regulator and (I think) the cold start valve didn't fix the problem. The idle is fine when the car is hot and oddly enough the idle evens out when she stands on the brake pedal.

I noticed that this fault code doesn't set the "check engine" light, so I assume that the 1-1-3 must have done it. If the AMM is not burning the crud off the wire, that might account for that.

She reports that her mileage is perhaps slightly less, but then it's also been 15 degrees or colder for most of the last week. If the AMM is crudded up, I suppose that could affect its function and cause the engine to run rich or lean.

Thanks! I cleared the codes so we'll see if they come back, and hopefully will get a break to be able to work on the car a bit. I'll pick up some contact cleaner and dielectric grease.

Thanks, Duane!