What is my ABS system trying to say?

I think my ABS is probably trying to say ba bye!

ABS light comes on as soon as the truck moves forward.

Codes:
C1233 Wheel sensor LF input signal missing
C1234 Wheel sensor RF input signal missing
C1939 Brake pressure switch Circuit Failure
C1095 Hydraulic Pump Motor Circuit Failure

Whew! Also, cruise control won't come on -- not sure if that is related to the brakes or not.

So, at first, did not have the RF input signal missing code so I tried changing the LF sensor, and added the RF code while keeping the LF code.

Have not pulled the master electrical plug off the ABS module yet but either I've got a corrosion problem in the plug or the ABS module itself is toast.

Anyone have any other ideas?

If the module, how difficult are they to bleed after swapping? Any pointers?

Hmmm, well, managed to get my hands deep enough to unplug both the master and motor connectors.

Both are spotlessly clean and reinstalling/reseating the plugs had no corrective effect.

Does look like with a bit of very tight quarters work, the ABS controller and solenoid control block can come off the ABS valve body without opening up the hydraulics.

Think I'll source a used ABS module and try swapping the electrics, assuming I can find the super small "E" driver needed for the screws.

Could be module but seems odd for all those codes at once, if it was brain dead then no codes

Diagram below

Well, Things might be improving....

Swapped out the ABS module and have lost the various and random wheel sensor and pump motor circuit faults, but the C1939 Brake Pressure Switch Circuit Failure remains.

Have spent some time with the EVTM and can't say I understand the darn pressure switch.

From the Ranger's EVTM, the switch should be OPEN when the brake pedal is not applied, and should pass voltage from the fuse box to both the ABS and Speed Control modules when the brakes are applied.

I've tried two different switches, and both are CLOSED without the brake pedal applied. Can't see both a brand new, and a used pressure switch faulting the same way.

Have tested the system with the double fuse recall harness for the pressure switch in place, and bypassed.

Digging further, the 1996 Explorer EVTM shows that switch should be normally closed, and open with slight pressure to brake pedal.

For what it's worth, Rock Auto and AutoZone both show the '96 Explorer and '02 Ranger use the same pressure switch so I've got a disagreement on my hands. What I'm seeing on the Ranger along with both Rock Auto and AutoZone web sites agrees with the earlier Explorer EVTM and disagrees with the later Ranger EVTM.

Very tempted to wire in a 5 pin relay off the brake pedal position switch. That way, it'd be easy to either supply voltage with the brake pedal applied, or remove voltage when the brakes are applied. Would eliminate the safety of the independent switch making the Brake Pedal Position Switch the sole provider of the brakes applied/not applied signals.

I used a '96 Explorer for the V8 conversion, but the Cruise Control module, ABS module and the Brake Pressure switch are all original to the '02 Ranger so I don't think I've installed an incompatible component.

I installed the '96 Explorer cruise control cable into the '02 Ranger cruise control module and have put nearly 50K miles on the conversion before loosing cruise control and gaining the ABS fault. Oddly, if I remember correctly, the fault occurred right after loosing a left front wheel bearing,. The ABS kicking in just before coming to a stop had me suspicious of the LF abs wheel speed sensor but I've replaced that censor and ForScan shows a solid speed signal that matches the right and rear signals.

Definitely frustrating.

And perhaps the plot thickens:

Symptoms remain with the Cruise Control Module unplugged, as well as with the Brake Pressure Switch unplugged.

Most oddly, I got the Ranger onto a closed course away from other cars/traffic.

ForScan drops ABS connection when the brakes are applied. Will instantly reconnect, but re-drops just as fast if/when brake pedal is applied. So, if I let the Ranger coast to a stop, I can use ForScan to watch each ABS sensor, but if I try to see if one of the ABS sensors drops while braking, I loose sight of all of the ABS system.

Wondering if despite the displayed faults, I need to be looking at the brake pedal position switch instead.

And maybe resolved! But why?

Think I've "cured" the issue, but don't exactly know why.

I'd carefully unpinned the power from the brake position switch and the brake pressure switch from the ABS plug and added a couple scrape wires from the used ABS system pigtail I'd cut out of a wreck in the breakers yard.

With both the Pressure switch and Brake pedal switch disconnected, I continued to get the ABS trying kick in every time I'd stop the truck until the system would fault. Weird.

Did find out that my copy of the Ford EVTM DVD is WRONG on the NO/NC action of the pressure switch. Like the hardcopy I've got of the Explorer, the pressure switch is NC and opens when hydraulic pressure is applied to the switch.

So, digging deeper, or maybe should have gone there 1st, pulled both front brake rotors and found a dent in the ABS tone ring on the left front rotor. The whole ring was in crooked and the point of impact was deeply scarred and way out of true from the rest of the ring. Something got in there, and then got back out. Did not see any damaged to the abs sensor so this too is weird.

With a new set of pads and rotors, the electrics all back together, no more issues. Whew!

But, WHY? Why would a damaged tone ring cause a P1939 fault code? WTF?