2 loose pins inside this connector. 1 pin broke off, after which fuel gauge stopped working. Had minor corrosion on a few pins as well.
Hey guys, my 2000 Ranger 3.0l Flex 2wd had the abs light come on Friday evening before leaving work. It drove terribly on the way home. Had transmission shift problems and the speedometer was going crazy. I did my research here and decided to change the sensor located in the differential. Today before changing it my O/D light began flashing and speedometer was not working. I replaced the sensor but the abs light is still on. I just did a KOER test and received a P1780 Transmission Control Switch code. Does anyone have any ideas on what the problem is???

 

P1780 means the OD Button(TCS) is not working

It is a momentary contact button that toggles between OD on and OD off
Check fuse #6 15amp, in cab fuse box
That sends 12v to TCS button, when pressed that 12v is sent to computer which "reverses" current state, so if OD was ON, pushing button turns it OFF and visa versa
Computer also turns on or off the OD light on the dash to indicate state

Every time you turn on the key the system is restored to OD on, it doesn't "remember" last state.

If you run a system test then you need to press the OD button at the correct time in the test or you will get P1780
TCS wouldn't cause shifting issues, OD would be on next time you started vehicle

And did the new VSS solve the speedometer problem?
Speed sensor is VERY important on 1995 and up Rangers

Do you have Rear ABS only or 4 wheel ABS?

Your picture is connector C309, under drivers seat and a problem connection on 2000 Rangers, there was a TSB
Google: 2000 Ranger C309

But I don't recall transmission issues associated with that connector, there could be just don't recall that.


On 1998-2000 Rangers speed calibration was thru GEM module, or 4 wheel ABS module, so which one you have is important.
Rear axle VSS sends its signal to the GEM or 4WABS module, where it is calibrated to 8,000PPM(pulse per mile) needed for correct speedometer readout and correct speed for computer to use when selecting gears in an automatic trans.

So very important to have correct speed

ABS light can be on because brake fluid is low, brake light fuse is blown, e-brake is not fully released, connector on ABS module is loose/corroded..............or speed sensor is not working

 

Yes. I replaced the sensor located on the rear differential on Sunday. Still had the same problem. I checked the C309 connector and had two loose pins, one of which broke off. I cut the wires of the two loose pins and connected together. Same issue. I'm thinking it may be a GEM .I'm taking it to a shop this evening. As for the O/D light, it was flashing so I don't see how it can be a fuse. Pretty sure it is 2 wheel abs. I do not have front hub assemblies. Just bearings packed in the rotors. Rotors have an abs ring, though. I really think it's the GEM at this point.

 

Brake fluid level is fine.

 

No wires going to the front wheels. Only have the rear abs sensor on the differential. Sounds like 2 wheel abs.

 

If RABS then GEM module is used to correct rear axle VSS to true speed for speedometer and computer, also cruise if so equipped.

If you have working cruise control you could test if set speed is stable, or if it drifts

 

No cruise control option. My guess is GEM

 

GEM fault shouldn't cause ABS light, just speedometer or computer issue

Rear axle VSS runs directly to the ABS module, these 2 wires are Spliced and run to GEM module.

The Pink/orange wire on the VSS should be a Ground wire, test that with OHM meter, low ohms to ground
Grey/black is the positive wire so high ohms to ground

VSS outputs AC Voltage, so not like 12v and ground system, but the pink wire is grounded.
AC Voltage is a sine wave voltage that goes to + voltage and then to - voltage, 0 volts is the mid line for AC Voltage, which is a 12v systems Ground, 0 volts
So with 1 wire grounded the VSS sensor just sends + AC Volts to ABS and GEM, the FREQUENCY of this Pulsed AC voltage is what indicates the Speed of the rear axle.

 

Might be the abs module then. Maybe GEM. I don't have the time right now to work on it. I work all day and go to school twice a week. I'm taking it to a trusted shop today. I'll let you know what the verdict is. Lol

 

Turned out to be the GEM module after all causing the ABS light. The corrosion and poor connection at the C309 connector below the driver seat was causing the driveability issues. Because they got a new module from Ford and it has to be programmed, my repair bill is $838. F me!

 

Thanks for the update

 

You're welcome! I'm still waiting for them to finish the repairs. I want my truck back!

 

If i want to swap out a GEM module with one from a junkyard what do i have to match up? (or can i?)

 

I think they have to be programmed but I'm not the expert on this particular part.

 

1998-2000 Ranger GEM
2WD or 4WD
Power group or not, i.e. power windows and locks
Keyless entry

Tire size(this is the programmable part)

I think thats it, wipers and lights are standard stuff any GEM would have

 

good to know thanks!

Also where does the abs wires go from the sensors? like they plug into connectors on the core support but then where? i cant see where they go after that. I may have a bad wire somewhere but hard to trace...

 

ABS speed sensors go to the ABS Module
Rear ABS or 4 wheel ABS modules are at different places

And 1998 to 2000 Rangers with 4WABS use the ABS module for speedometer 8,000PPM conversion, so not GEM module

RABS Rangers have rear axle speed sensor wires spliced and they run to ABS module AND GEM module, GEM does the speed conversion

 

I've got a similar problem...I think.
Not a car guy.
Just got a 1998 2WD V6 4.L Small cab Funky Green 155K miles for daughter.
Figured I should try to fix the safety functions first. ABS light on. 4WABS
Don't recall code but it mentioned the fronts. I replaced both front sensors. Different scanner says "NO INPUT" from both/either sensor.
This is where I stopped. I do not know where to go from here.

 

Long, long story, very short...wires leading to and from connector under driver's seat were corroded inside the wire insulation. Ended up taking it to a trusted mechanic with electrical knowledge and that is what he found. He had to cut back more wire that he wanted in order to find clean copper, but that was the issue.