1998 Ford Ranger XLT 3.0L V6 (4R44E Auto)
Do apologize for the long post, but want to explain everything that has been done so far. So picked up this little pickup recently and have been trying to figure out how to fix it. Body was in pretty good shape and only had 103,203 miles on it when I bought it. Now I know it was going to need some work, but I picked it up cheap! So brought it home and started to look into what was wrong with it. So far what I have found wrong with it:

1. Check Engine Light On
2. ABS Light On
3. Airbag Light Flashing & Stays On
4. Auto Trans Shifting Harder Than It Should
5. Exhaust Needs Replaced
6. AC / Heat Blows Thru Defrost Only

First repair was the exhaust. Drove it to a local shop nearby my house and got the muffler replaced and now truck sounds great. Brought It home and started to pull codes. Airbag was showing a code of 27. Just need to fix the Airbag light on the Passenger Airbag Disable Module. Then pulled the OBD II reader out and got these codes:

P0301 Cylinder 1 Misfire Detected
Alright I knew this might happen since the owner told me it had low compression on cylinder one. These engines have a nasty habit of having crap heads and the valves will recess sometimes. So no big deal, will buy new heads and replace them, engine shall run great afterwards! Went and bought two new heads, gaskets, thermostat, etc! Just got to install them now!

C1234 Wheel Speed Right Front Input Signal Missing
ABS Sensor on front right wheel was not working at all. Bought new sensor with harness and replaced it. Cleared codes and ABS light has not returned.

C1102 Acceleration Switch Circuit Malfunction
ABS Sensor on the center of rear differential. Bought new one and replaced. Cleared codes and ABS light has not returned.

Repairs Done So Far:
Replaced ABS Sensors and cleared codes. Also found out someone had replaced the vacuum assisted hubs with manual locking ones. This was causing a vacuum leak and the AC / Heat was stuck blowing thru the defrost. Bypassed the vacuum module that sends the vacuum to the hubs and now the AC / Heat blows thru the vents like it should. Like mentioned before, I replaced the trouble ABS sensors and so far the light has not returned. The miss-fire will be fixed after I of course replace the heads. Muffler was replaced and Airbag light figured out.

The Strange Part:
So before I did any repairs on this truck, the speedometer & cruise control worked! The reason I mention this is because I have read a lot of posts saying if that ABS speed sensor goes bad, then usually these functions don’t work or they act up. Now I have replaced this sensor, but the transmission is still shifting harder than I would like. So I took it to a couple transmission shops that are local and the first shop just wanted to rebuild it, of course. The second shop was more honest and pulled what codes they could and told me it was the Vehicle Speed Sensor fault. Paperwork showed this:

Recommended Repair: CK output speed sensor (-0- Reading)
Codes: P301 Cylinder 1 Miss-Fire, P1808 4WD indicator, P1804 4WD High Indicator, 3 B Codes, P0500 Vehicle Speed Sensor Fault

Mechanic onsite told me that he wasn’t getting any reading out of the speed sensor. Now they told me there should be one on the side of the transmission or transfer case. This sensor would cause the transmission to shift harder. That made sense to me and I brought it home. I started looking for this sensor on the side of the transmission and found nothing of course. From research, seems this model doesn’t have a VSS sensor and the ABS sensor in the rear differential plays a dual role.

So what I would like to know:
Now since I replaced this sensor and still having the same issues, plus the speedo and cruise control works, WTF? Could I have bad wiring and need to tone the wires to see if there is a break somewhere? But even if I had bad wiring, then how the hell is the other components working? In theory, I shouldn’t have a working speedo and cruise, etc. I am scratching my head over this because none of my problems match what others have dealt with? Any suggestions?

 

Welcome to FTE.

You've been busy on this one. I see you don't have any replies, so Ill see if I can get things started.

Seeing as how you seem to like doing your own trouble shooting & wrench turning repairs, if you have, or can borrow. or come by the inexpensive ELM scan tool, running FORScan, or the like diagnostic software on the viewing device of your choice as discussed here, https://www.ford-trucks.com/forums/1...-scantool.html, it can scan All of the vehicle computer/controllers for trouble code clues & can read & if we wish, can put up live sensor data feeds to our viewing device for monitoring, so should be able to provide suggestions for answers to the ABS & tranny shifting questions, as it can query those controllers for trouble code clues & put up live data for monitoring on your viewing device if you want.

I had a like rear speed sensor dilemma on my 99, that set the ABS light off & had None of the tranny shift, cruise control, or speed-o problems that were also supposed to be present if the rear sensor is bad.
Apparently/I'm guessing now, if we have 4WABS, the computer must be able to query the front wheel sensors for info to operate those systems, as they weren't acting out when I performed my diagnostic test drive after the ABS light lit up. So I in error put the rear speed sensor low down on my trouble shooting suspect list & moved on to pulling, cleaning & inspecting the front speed sensors, which were ok/no ABS light out joy.
It was then that I researched & decided to opt for the ELM & to run FORScan, to be able to query the ABS controller that my Actron CP9145 scan tool couldn't access & that got me back on track, as the ELM/FORScan combo said the danged rear ABS speed sensor belonged High up on, not low down on, my suspect list as it had a trouble code that said rear speed sensor short to ground, or open circuit, I found it to be Open Circuit.
So, like you I was asking myself how in the world could all those other systems function ok without it's signal.....unless the computer is able to adapt on 4WABS systems & use front wheel speed sensor input, which I now suspect it can but haven't been able to yet confirm.

Anyway, some thoughts for consideration, let us know what you find.

 

Thanks pawpaw for that information. My father had bought a few of them China made blue ELM327 but I couldn't seem to get them to work. Guess he had bought the wrong ones because alot of them have different pin connections and won't allow communication with certain vehicles. I need to find one that will.

 

As posted later in that thread, it's reported that the blue tooth model sold by BAFX on Amazon, works fine with the blue tooth version of FORScan on a smart phone, if your thinking that way. I chose to use a WiFi model with my laptop & it's been fine. As suggested in the thread, buy from a vendor that has a good reputation, with a phone # that works & will back up in writing what they sell, like BAFX, ect.

Let us know what it finds by posting All trouble code Numbers.

 

Still haven't gotten around to looking at the transmission issue yet, but I at least got the engine done! Rebuilt heads, new timing chain & gears, water pump, gaskets, & power steering pump been replaced. Engine runs great, but now I got some kind of slack somewhere. I can feel it when I slow down or come to a stop. Also does it when I take off. So gotta find that problem along with figuring out this transmission issue.

 

Ok good to hear the engine rebuild seems to have gone well & your satisfied with the results.
Does the tranny problem seem to be slack in the drive train?

 

Not to jump in, pawpaw usually handles these things.

I am sure you probably have already checked and greased your u joints? Wearing ujoints will be misinterpreted as a transmission problem because they clunk when it shifts. I have seen worn u joints pass the "push pull twist" test but once they are replaced the "transmission problem goes away. A common test is to sit in Park then shift to Reverse, then to Park, then to Drive and see if it clunks. But I have seen bad ujoints get past this test. Another symptom of wearing ujoints is a washboard feeling while driving. It feels like you are running over bumps but the road is clear.

Just something else to consider