1986 Ranger, 2.9 liter

[rrod]

Any one know exactly where the EMW module is? Tried to get the truck SMOG tested, they won't test because the emission light will not come on. This is in California. Its not the light. I thought it was because I had no continuity through the light socket. It was the socket. I as able to fix that. But no go. I have contuity through the circuit membrane, but no voltage when the key is on.

 

[adsm08]

The engine computer should be responsible for that. The light should get power with the key on, and then the computer grounds it to prove out or when a code is set. Some of them had a separate unit up above the glove box that was kind of a maintenance reminder and would turn the light on after so much time.

 

[RonD]

Not sure if the 1986 2.9l Rangers had a working CEL(check engine light), also called MIL(malfunction indicator light)
There was a place for it in the dash but no bulb and no wires

Calif. was different but not sure in 1986, in 1988 Calif engines used MAF sensor and had CELs

In the engine bay find the OBD plug-in, it will be on the main wiring harness usually passenger side by firewall

It looks like this: https://www.stangnet.com/mustang-fo...entid-58312-stc-1-d-1242744354-20-gif.560550/

On this diagram you see the Yellow("tan") wire and its slot

As asdm08 said, this slot should be a GROUND with key on, and then No Ground after engine starts
Comes from pin 17 on the EEC-IV computers


CEL Bulb will need 12volts on 1 terminal when key is on, then other Bulb terminal connected to the OBD slot that is a GROUND with key on, and no ground engine running

You don't use the RED jumper wire in drawing, thats just used when you want to read OBD codes

 

[alwaysFlOoReD]

In my Canadian 1986 2.9 Ranger there is no cel/mil light. I had to tell that to the inspector when getting a salvage inspection.

 

[rrod]

Thanks for the replies. I did confirm there is no check engine light. The circuit membrane covers the socket area, so its impossible to put one in. I think I found where the EMW module for the emissions light is supposed to go (above the glove box) as stated by adsm08. Someone must have removed it. Thanks again.

 

[RonD]

Emissions light came on at 60,000 miles, a reminder to service the system, info here: http://ww2.justanswer.com/uploads/jmcdo28/2009-01-01_192346_emissions.pdf

So no reason Emissions light should be on, SMOG test would fail if it was on, not if its off, off is GOOD

 

[adsm08]

Thanks for the replies. I did confirm there is no check engine light. The circuit membrane covers the socket area, so its impossible to put one in. I think I found where the EMW module for the emissions light is supposed to go (above the glove box) as stated by adsm08. Someone must have removed it. Thanks again.

The emissions module thingy was optional, but they were also prone to failure. They had a little reset button on them that would dry out, crack, and cause you to be unable to reset the light. A lot of the ones that were installed got ditched over that. I've owned 4 1st gen RBVs, of the 3 Rangers only one had it, and I've never looked on my b2.

If the membrane is closed over the CEL bulb its pretty easy to argue that it was not factory equipped. It can be added though by just cutting out the hole with a razor and installing a bulb. All the wiring and software should be there already.

Emissions light came on at 60,000 miles, a reminder to service the system, info here: http://ww2.justanswer.com/uploads/jmcdo28/2009-01-01_192346_emissions.pdf

So no reason Emissions light should be on, SMOG test would fail if it was on, not if its off, off is GOOD

A lot of the US states that do emissions look for the light to prove out on start up. What they are really looking for is that it is able to work and hasn't been disabled in an attempt to hide something else that would fail.

 

[19Walt93]

RonD is right, it was a service reminder and not a MIL. Early EEC IV vehicles didn't have MIL's so you could have a sensor fault and the processor(we didn't call them PCM's yet) would plug a good value for the sensor into the equation and you wouldn't know there was a problem. Then you'd forget to shut off the lights on a foggy morning and find a dead battery at the end of the day. Once you jump started the car there was no longer a good sensor value in memory so the problem made itself known. EEC V/OBD II is so much better.

 

[Shran]

Good lord, I would hate to be troubleshooting something like this. My F150 has an emissions light and it has come on occasionally but definitely NOT at 60,000 miles (yes, I was driving the truck then ) and the stupid thing would blink once in a while. I think I finally removed the bulb. I don't recall ever seeing the module in any of my Rangers though.

 

[rusty ol ranger]

If the inspector is that worried over emissions on a 33 year old truck i would just add the bulb like adsm suggested and run a jumper off the fuel pump relay or something. That way when you turn the key on itll come on and go off with fuel pump prime