Cel 94, obd1?

For those that haven't been reading my posts on the forum. I just picked up another new old truck it's a 94 super cab 4 L manual 4 wheel drive. We even placed the transmission over the weekend. That part while terribly difficult for an old broad and an old guy that still has all the tools and jacks for the work actually went pretty well!


Ok questions.
Where do I find the test connector on the 1990 Ford Ranger 4.0? I understand it's a blinking light read out.
Are these worth having? https://www.ebay.com/p/Innova-3145-Digital-Obd1-Code-Reader-for-Ford/2256086897

This truck also has the RABS system on the brakes and of course that light is on also. And I also understand that code can be read out by shorting out the module in it certain plug under the dash?
In the meantime I may check and see if we short it or burned oxygen sensor wires or any other wiring when we were doing the mechanical work.

Truck ran really well, when test driving and when we test drove the truck before I bought it and took it to my friends house!

Well this morning I jumped in said truck to make the trip back to my house (a little over a hundred mile trip on the turnpike.)

Within a half an hour the CEL came on and stayed on, and probably sent into engine into limp mode? it was sucking up gas like it had a hole in the tank and really running strange but I did make it home!

And of course it's raining and cold again. Bad news depending how you look at it? I have 2 old trucks! Good news? (depending on how you look at it) I can drive one while the other is being worked on!

On my 1994 4.0l, manual trans, 4x4, OBD1 connector is on firewall side of engine fuse box.
Might still have a black plastic cover over it.

1990 will be on the main wiring harness and probably on passenger side of engine bay since I think computer was in the cab behind passenger side kick panel that year, so follow main wiring harness where it comes out the firewall and you will find it.

I have found them as far forward as the Rad support, but wasn't 1990

No, never heard of anything in the cab that can enable reading OBD1 codes on Rangers

1994 will use 3 digit OBD codes, for 1990 4.0l not sure if it will be 2 or 3 digit, but I would think 3 digit, I think all MAF systems used 3 digit, but have not seen ALL of them, lol.

On my '93, there is a test plug over by the engine compartment fuse/relay box. You put a jumper between 2 pins and the CEL blinks the codes on the dash. If I recall correctly, there is a good tech article explaining it with pictures. Check the how to teach. It's pretty easy, but I haven't done it lately. So I don't want to try to give you detailed instructions.

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ericbphoto said:

On my '93, there is a test plug over by the engine compartment fuse/relay box. You put a jumper between 2 pins and the CEL blinks the codes on the dash. If I recall correctly, there is a good tech article explaining it with pictures. Check the how to teach. It's pretty easy, but I haven't done it lately. So I don't want to try to give you detailed instructions.

Sent from my SM-G960U using Tapatalk

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Thank you gentlemen! for now I'm going to unwind unpack and relax. I'll get the truck in the back of the house start looking for some Elementary stuff before I go over to the shop that supposedly specializes in Automotive Electrical he was a member of a boat club I was in.

Small update:
I just drove the truck around and put it in my backyard and the CEL did not come on. and it's running kind of okay but it's definitely not running right.

Add, Checking spark plug wires and coil connections to the list.

Good night! Lol

Diagnostic port is under the hood, probably near the fuse block. Ford like to keep the OBD1 ports near the computer.

I have always preferred a code reader to flash codes. It takes the uncertainty out of counting and pausing and such. For $32 the Innova probably isn't bad but there are other better ones out there. For a Bakyardigan I'd probably recommend the Blue Point Micro-Scan2 or 3. I had one for a while and it was pretty nice. I traded it on a used Solus that was a few years out of date but had all the goodies.

EDIT: Hood. It is under the hood.

adsm08 said:

Diagnostic port is under the dash, probably near the fuse block. Ford like to keep the OBD1 ports near the computer.

I have always preferred a code reader to flash codes. It takes the uncertainty out of counting and pausing and such. For $32 the Innova probably isn't bad but there are other better ones out there. For a Bakyardigan I'd probably recommend the Blue Point Micro-Scan2 or 3. I had one for a while and it was pretty nice. I traded it on a used Solus that was a few years out of date but had all the goodies.

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I'll probably keep it under $50 it's just a PITA going to a shop every time I need codes read. I'm not into paper clips never was lol Thanks!

94 ranger odb1 connector is on drivers side, between the mc and fender.

Ewgoetz said:

94 ranger odb1 connector is on drivers side, between the mc and fender.

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Found it! thank you! right where you said it would be!

dont forget theres two tests koeo (key on engine off) and koer(key on engine running). each test will provide different codes

JOLENE_THE_RANGER said:

dont forget theres two tests koeo (key on engine off) and koer(key on engine running). each test will provide different codes

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I picked up the innova reader. Going to go out there this afternoon and play with it!

Truck had a major limp mode event on the hundred mile trip back to my house last Sunday, I was not happy! it was shaking and missing and sucking down gas like there was a hole in the tank! the CEL has not come back on since, but I haven't been driving it either.

Denisefwd93 said:

I picked up the innova reader. Going to go out there this afternoon and play with it!

Truck had a major limp mode event on the hundred mile trip back to my house last Sunday, I was not happy! it was shaking and missing and sucking down gas like there was a hole in the tank! the CEL has not come back on since, but I haven't been driving it either.

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ive never seen that lil guy before! i might have to get one too

lol I've been Code reading dependent for too many years, time to take the module by the prongs! (bull by the horns?)

My friend is trying to convince me to just change out the PCM because that is what LIMP mode means LOL according to him DON'T THNK SO!

BUT, I ido have a manual 4.0 PCM that I got about 2 years ago for the auto to manual swap I'm not going to do on my other truck. 93 long bed)

Day three,

step 1
Plug in reader

Step 2
turn on ignition.

Step 3
press and hold test button!

Step 4
Stand and watch codes coming up!

Step 5
write down codes come in house warm up, post codes here on site!

111, 114, 116!

Step 5

looking up the codes

111 system pass

114 Air charge?

116 temp, I do know the thermostat was acting up because the temperature was fluctuating cold to medium maybe it doesn't have a thermostat or maybe it's got a bad thermostat haven't checked that yet.


Haven't done key on key on engine running yet.

What's bothering me are these (stored) codes which don't seem to be major, enough to send the truck into limp mode, when I was on that trip back to the house??

I did find and plug a small vacuum leak.

I plan to put in a new thermostat.

Broken dipstick tube will that affect the vacuum?

I know temperature and vacuum effect oxygen sensor readouts, basee on what everybody tells me should I start driving a truck?


Timid? me? never! always!!!

I'm confused - are those in the order received? To my knowledge 114 and 116 aren't used for continuous memory / stored codes, but you listed them after a 111 which should have taken you out of KOEO results.

On the flip side, if you actually got 114 and 116 as KOEO and then 111 for continuous, it sounds like you just ran the codes without the truck warmed up.

fastpakr said:

I'm confused - are those in the order received? To my knowledge 114 and 116 aren't used for continuous memory / stored codes, but you listed them after a 111 which should have taken you out of KOEO results.

On the flip side, if you actually got 114 and 116 as KOEO and then 111 for continuous, it sounds like you just ran the codes without the truck warmed up.

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thanks for the quick response! They did not come up in that order. Just the way I wrote them down.

I did it cold turning the key on to run the reader and just to find the codes that made it run so badly in failsafe on the way home last Sunday.

later today I'll start start it and run up to temperature but I know it has a bad thermostat and hi idle