I am getting 311, 113 and 231 OBD codes in my 91 245.

113 and 231 may be related to the O2 sensor which was replaced maybe 6 months ago with a Bosch Universal sensor. I have cleaned connectors to the sensor with CRC

311 is for missing speedometer signal at the cluster or speedometer. I know the cluster is not correct for the year, it has an 87 date code on it. Is there anything I can do to correct this? I am having idle problems and idle air valve and TPS work fine and everything is clear. I get a 332 code checking TPS off idle and Bentley says I should get 334? Is this OK or is there a problem?

Thanks
Dan

Hi,

I can't help with the idle problem, but I also had an 87 cluster in a 91 240 and had the 311 code.

This made my cruise control inop, and Mr. B told me that the 91 gets the speed signal from the blue/black wire at #6 on the big round plug with the half moon locator pin.

If you release that pin and stretch that wire to the double spade terminal on the 87 cluster, you should have a speed signal. The double spade is the one some people mistake for the tach wire and then they have a fried speedo.

I didn't have any idle problems without the speed sensor, but apparently the computer uses that info on deceleration.

Peter

What did you use to make the connection to the spade fitting? Splice on a female spade connector?
Thanks
Dan

If you do that, don't cut off the old terminal that goes in the big round connector. Splice in just behind it and put a sleeve or tape over the exposed terminal, so you can use it again in the original configuration when you get the correct cluster for this car.

There really is not any interchange to speak of over the years with electronic speedometers. The 91 cluster is the same with or without ABS, but it is different from a '90, and different from a '92. Unless you are into detailed mods or don't care about some features (e.g. ABS and warning lights) the best approach is to have the correct year cluster.

So do I need to remove the connector from the round plug?
Thanks
Dan

311 code went away temporarily and the idle seemed fine. A few days later it is back any ideas on this one?
Thanks
Dan

I'm confused. Which cluster did you wind up leaving in there, the 87 or the 89?
--
Art Benstein near Baltimore

By the time a man realizes that his father was right, he has a son who thinks he's wrong.

It is the 89, 311 clears for awhile then it is back. Could this be related to leaving #6 pin attached to the circuit?

Now seem to be getting 113 could this be a ground issue on the O2 sensor? Looking for a way to add a ground.
Thanks
Dan

In the 89 cluster pin 6 is tied to the double spade, so that isn't it, if you're sure it is an 89. 89 is the first LH2.4 year, and LH2.4 brought OBD and VSS feedback to the ECU. This happens on pin 6. If you leave the 89 in place, then the splice to the spade lug is redundant. Speedometer never falters?

The 113 is what the ECU sets when it gives up entirely matching the injector duty cycle to the AMM output for closed loop (input from the O2) and gives you limp-home. Make sure it repeats (by resetting via fuse 6 and trying again) before replacing stuff. You can guess at grounds, but nothing beats actually measuring the voltage from the oxygen sensor.
--
Art Benstein near Baltimore

Being right is highly overrated. Even a stopped clock is right twice a day.

Speedometer has always worked fine. Sounds like I don't need the splice to the spade connector on the cluster?

I reset fuse 6
I was unable to get a 6 month old O2 sensor to read anyhing but 4 volts so I was wondering if I lost the ground through the exhaust

The car stumbles and has a lack of power intermittently, it does feel like limp home but the AMM was replaced with a good spare and doing the same thing.

I replaced the snorkel with a spare even though the original looked good.

This is beginning to sound like Dan Marino's problem

Thanks
Dan

"I was unable to get a 6 month old O2 sensor to read anyhing but 4 volts so I was wondering if I lost the ground through the exhaust"

That's pretty weird. I'd want to focus on that keeping in mind the possibility of operator error. I just can't picture that amount of rust in your neck of the woods. If it is bleed from the heater, disconnecting the heater wires (double plug) would change the reading.
--
Art Benstein near Baltimore

Don't find fault, find a remedy. (Henry Ford)

Rechecked O2 sensor and it was fluctuating between .2 and .9 volts so it's OK

After a couple days of use no codes reappeared.

This AM car started, backed out of the driveway, stalled and would not restart.

No spark, swapped the fuel relay no go. I was going to swap the power stage out but decided it was quicker to try the ECU first, and it fired right up. Apparently dead 951 ECU. I have had one or two of these fail over the years so I am not too surprised.

My wife went across town and reports it is running fine with no missing or chugging as it was previously doing. Hopefully it's back to a reliable runner just like the other 3 I have.

Dan

I wouldn't be too quick to toss that 951, unless you think it got some water inside. Not sure of this, but I think you would get spark even with the 951 disconnected. Sounds like it could be a poor connection, likely to bite you again later. In the 91, prime suspects are wiring and fuse terminals at #6, and the 12-pin junction between the cabin and engine wiring harnesses, left of the glovebox. Both computers need power from that troublesome fuse 6 source.
--
Art Benstein near Baltimore

Before I got married, I had six theories about bringing up children.
Now I have six children and no theories. (John Wilmot)

Well haven't fixed it yet, no codes but the intermittent stumbling /missing is still there. Once it starts stumbling it does not go away right away and sometimes seems like going around a corner cures it?

Just cleaned the power distribution block behind the battery and the large grey connector on the fire wall. It was stumbling when I restarted but did a hard left hand 3/4 circle in a cull de sac and it cleared up and is running fine again. I'm pretty sure the stumbling and slight backfiring will return.

Tank is over 3/4 full and I can hear the in tank pump running.

Any ideas?
Thanks again
Dan

Nothing beyond guesses, Dan. One characteristic of the poor connections at fuse 6 that I mentioned previously is the OBD will report no codes (111) because breaking the power circuit clears them. And once they are cleared, the fuel trim is reset, which makes things run like doo-doo until it adapts after 10 min/10 miles whatever. Tough one to catch in the act.
--
Art Benstein near Baltimore

Blowing out another's candle will not make yours shine brighter.

Thanks Art.

I just put another new fuse in #6 if that doesn't do it I guess I need to remove the fuse block and go from there. I was able to wiggle the connector on #6 so they should have good contact, I don't see any corrosion and the connections appeared tight.

Thanks again
Dan

"... I don't see any corrosion and the connections appeared tight."

That's why I say this is a tough one to catch. Our sense of sight is often not up to recognizing the barriers to electron flow.

http://cleanflametrap.com/emfuse.html

--
Art Benstein near Baltimore

Be careful of your thoughts, they may become words at any moment.

"... I don't see any corrosion and the connections appeared tight."

What I meant here is I don't see any significant corrosion like you might expect from a leaking wind shield or something.

I like the idea of a spade fuse replacement for # 6, I think I will do that.

The 91 has a couple of trouble free days of operation since paying some attention to the fuse block, so fingers crossed still on this one.

Thanks
Dan

Thanks Art

I was going to check the ECU on my car before condemning it. I will also check the other items you mention.
Thanks again
Dan

ECU is good as Art said it would be!

So this whole thing must have been some poor or oxidized contacts / connectors. I have since cleaned contacts at ICU, ECU, 12 pin connector connecting interior harness to engine harness, engine grounds, power stage, AMM, and fuses 4 and 6 contacts. There are no water leaks in the cab so this was apparently just 25 years of oxidation.

Engine is now running fine and so far no codes have returned but I will keep an eye on it.

Thanks Art and all others who have replied.

Dan

I was going to recheck that today but ran out of time with the car.
Thanks
Dan

OK, I have mislead you Art, somehow I managed to get the 87 cluster back in the car, blame it on brain farts!

89 cluster is now in the car but looks like I created the SRS light to go on, I will see if I can get the fault code and reset the light the next time I have access to the car.

I left the blue/black splice from # 6 pin on the round plug off the spade connector as I guess I don't need it?

I will see how it runs and if any codes reappear over the next couple of days.

Thanks
Dan

If it has an SRS light, then it is at least a '90 cluster. Maybe built in 89.
--
Art Benstein near Baltimore

The reason a dog has so many friends is that he wags his tail instead of his tongue.
-Anonymous

OK, it was stamped 89 but don't recall the month.

Will I be able to clear the ABS light using the 90 cluster in a 91?

I will see what happens over the next day or two.
Thanks
Dan

Thanks Art I will do that
Dan

Thanks maple bones I did recall seeing something like this on the BB but couldn't remember the specific years involved.

I did try an 89 cluster but it gave a bulb out light that bothered y wife so I went back to the 87.

I will try the swap as described while I keep an eye out for a 91 cluster non ABS.

I had another 91 but it's cluster was incorrect also.

Thanks
Dan