How to solve this 1/4 light issue?

Here's what happened:

I cleared the codes and took the 348 out just now. It ran great then the 1/4 light lit for 3-4 seconds.

Then, about 5 minutes later the 1/4 light lit for another 3-4 seconds, this time with 1/2 the engine power lost during the 3-4 seconds and then full engine power came back and light turned off.

I pulled the codes. There were two. The first was:

1211 (Lambda regulation Additive value for self adaptation (O2 sensor or coolant temperature sensor or MAF)

and the second was:

1112 Engine coolant temp sensor.

I am assuming that each of those codes correspond to the 1st and 2nd time the 1/4 light came on.

With that in mind, it means that the 1112 code corresponds to the time when half the engine power was lost during the second appearance of the 1/4 light for 3-4 seconds.

The question is how can the 1112 Engine coolant temp sensor result in half the engine power being lost?

Any input of what I should do here? How to fix this?

Thanks,
Dean

 

I found www.the348.com super useful when I was diagnosing a 1/4 light recently.
Mine turned out simply to be an O2 sensor which was easily solved with a $100 generic replacement.

It seems yours also code be a fault coolant temp sensor.

Search for 1211 on this page :

http://www.the348.com/technical/Tech/348.html

Looks like it may have some information relevant to your issue.
Hope it helps.

Simon.

 

That's where I got the info from. My dilema is that I want to know which is the one that is causing half the engine power to be lost for a few seconds.

Did yours lose power? What code did you get when you replaced the O2 sensor. I am thinking of replacing the sensor as a start.

Thanks

 

Dean I sent you a reply to your pm. Was it a Slow Down light or a Check Engine light?

 

You've got two error codes pointing to a coolant temp sensor problem. That could be a failed coolant temp sensor (348's have 4 of them) or two, or a bad wiring connection to the temp sensors.

What happens is that Motronic 2.7 has a very, very rich fuel to air "map" for extreme-cold weather.

Well, a bad coolant temp sensor is telling your Motronic ecu that it's as cold as possible.

So you run too rich. Except that your O2 sensor detects that you are too rich and signals a Motronic ecu to lean out the fuel...which works until the O2 sensor gets so coated with fuel/carbon over time that it goes bad.

In the meantime that extra fuel (before the O2 tells the computer to lean it out) heats up your cats.

Well, our cat temp ecus must not be very accurate because I've had one shut down a bank of cylinders (i.e. half of the 348's engine) *without* triggering the SLOWDOWN light. In fact, I've even had it happen without triggering the "cat temp too high" error code in the Motronic ecu.

Anyway, I'd suggest doing a couple of easy basic things first. Install a new 1/4 O2 sensor, preferably a cheapo generic unit because if it takes you a while to correct this problem then you are going to ruin the next O2 sensor. Then clean your O2 electrical connections that are under your air filter area (be sure to keep all liquids away from your actual O2 sensor units, though.

Next, clean (contact cleaner first, then Stabilant 22a) your MAF electrical connections that are inside the black cable that attaches to each.

Then clean your throttle position sensor electrical connections.

Finally, give an extra thorough cleaning to the ground cable on the back left side of your car that goes from your tranny to your subframe...at both ends.

Reset your Motronic ecus by turning off the battery for 20 seconds while the motor is cold (and off), then start your 348 and let it idle (without touching anything, especially the throttle or any electronics) until you hear a cooling fan come on (i.e. the water temp is up into the normal operating range).

Now go drive your 348 to see if your codes reappear with your new O2 sensor.

Of course, eventually you are going to have to do more than just the basics. You are going to have to replace at least two coolant temp sensors, and they are beneath your intake plenum in the middle of your engine (on top).

...and when those are being replaced, insure that their electical connections are first cleaned and then later treated with a coating of Stabilant 22a.

 

What about if the engine is still cold and 1/2 of the engine shut down and when its hot...everything runs well.....so is this consider the same problem...?

 

Perhaps not. Could be a faulty exhaust ecu.

 

ND,

About a month ago, it did the same thing (shutting down half engine power for a few seconds). So I cleaned the O2 sensor connection at 1/4 side and applied treatment to the connectors under the air filter and the problem went away but only to appear again this past weekend. By the way, I used the CRC Dielectric Grease on the connectors (not stabilant 22a) http://www.crcindustries.com/ei/content/prod_detail.aspx?PN=03082&S=C

- I ordered an O2 sensor complete with the connectors and will replace the 1/4 side once I receive it.

- When you mentioned to clean the (contact cleaner first, then Stabilant 22a) your MAF electrical connections that are inside the black cable that attaches to each. Does this still apply with a new O2 sensor?

- How doI do this and where is it located? : Then clean your throttle position sensor electrical connections.

- "Finally, give an extra thorough cleaning to the ground cable on the back left side of your car that goes from your tranny to your subframe...at both ends." ..... If this was a problem, wouldn't the 1/8 side be affected too?

- Should I replace at the two coolant temp sensors beneath the intake plenum in the middle of the engine now or wait until I check what happens after the above has been done?

Thanks,
Dean

 

You certainly want to clean the easy to reach electronic connections first.

Here are the MAF and TPS (throttle) sensor electrical data connections (left side shown = 5/8 cylinders, you want 1/4 cyls on right side):
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Here are the two ends of the tranny-to-frame ground connection. Clean both ends.

You can reach both of these connections from the top, and you can reach them both from below. Your choice. Nothing needs to be moved out of the way to get to them, either. Just reach in clean with contact cleaner (preferably with the bolt loose/unbolted) and then coat with Stabilant 22A (and of course, bolt it back in).
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ND,

Thanks for your time and help. I have been using CRC Dielectric grease http://www.crcindustries.com/ei/content/prod_detail.aspx?PN=03082&S=C
as a contact preserver and not Stabilant 22a . Is that good?

 

I have no idea!

 

They are totally different items.

It is a material that is placed in an alcohol suspension. You swab it onto an electrical connection (don't worry about touching plastic parts), and re-connect the plugs. The alcohol evaporates and the Stabilant is left on the metal bits. It is inert on plastic and rubber -- it only works on conductive metal surfaces. It is a patented item that literally enhances ('preserves' is a better word) electrical contact at the connection point.

From the Stabilant product literature:
Stabilant 22 is an initially non-conductive block polymer which when used in a thin film between metal contacts becomes conductive under the effect of an electrical field. This occurs at an electric field gradient such that the material will remain non-conductive between adjacent contacts in a multiple pin environment. In addition, Stabilant 22 exhibits surfactant action, as well as lubrication ability providing a single component resident solution to virtually all contact problems. When applied to electromechanical contacts, Stabilant 22 can provide the connection reliability of a soldered joint without bonding the contact surfaces.



* Dielectric grease is like a parka. It prevents moisture, heat, etc. from getting into a connection point and causing failure. By itself, it doesn't really do much for the electrical point.

* Electrical contact cleaner, is simply that. It cleans an electrical contact so the connection point is more 'pure'.


For me, I use electrical contact cleaner (some CRC junk that I found at PepBoyz), first. I spray it on, and let it dry. Then, I swab some Stabilant-22a onto the connection point and reconnect the plugs before it dries.

 

So if I cleaned the connectors then applied Dielectric Grease and re-connected them, will that not protect the connection and keep it working?

 

Unknown. It may or may not be good for data connections.

On the other hand, contact cleaner plus Stabilant 22a is known to be good for data connections. Much safer bet.