ABS light came on my '95 Ranger w/ an OBDII setup. Using an Actron scanner, I got a "connection failure" message when trying to read or even erase the code history. Checked the pin connection at the radiator support core-mounted control module (several times) . The pins were clean w/ no corrosion. Checked the resistance at the 2 front wheel sensors and the rear axle sensor. All were within specs. Checked the surface of the 2 front sensors for debris. Both were clean. The fuses in the engine compartment and the cab interior fuse box were all good and I even cleaned up the fuse tabs. Could the "connection failure" be an indication of a failed control module? I have no knowledge on how to check the module. The cheapest refurbished unit online is around $125. Don't want to make a $125 mistake.

 

Ok, bought a rebuilt control module. Now getting a Code #C1096 Hydraulic Pump Motor Open Circuit. Checked the connections and they are clean. Any other possibilities as to the open circuit meaning?

 

Replaced the 2 relays in the box adjacent to the engine compartment main fues/relay box. Also swapped out the ABS pump motor assembly with a known working used one. Still getting the same message on the ABS scanner. Any ideas out there?

 

The fault code C1096 indicates a fault has been detected with the hydraulic pump motor. Meaning the most likely culprit is either the HCU or the ABS control module. You may have received a dead control module, it happens even with refurbs (more often with refurbs actually). I would send it back in exchange for a different module. But before you do, do a continuity test of the wires leading to both the control module and to the pump. The connections could be clean but there can always be a broken wire somewhere in the circuit.

Here is a link to a wiring diagram for a 1995 2.3L Ranger. Let me know if you have the 3.0L and i'll send you a link for that diagram.

http://www.mediafire.com/?s15t2q17vqj1r4m (PDF)

 

I have the 4 cyl 4x4. Thanks for the diagram. I did another continuity test of the wires. For the pump motor there is a tan/red wire that goes from the control module to both the pump motor and one of the two relays. And the other is the ground that goes to both a 2nd relay and the pump motor.

The grounds from the relay and pump motor indicate nary any resistance. Alls well there.

Testing from the wire just outside the control module plug connector to to the relay female connector I get almost nary any resistance so that wire is good too. But from just outside the control module plug connector to the pump motor connection pin I get about 22% resistance. Testing from wire to wire from just outside the pump motor plug connection I see nary any resistance, so the plug connector is good. So the resistance is in the wire between the control module plug and the pump motor connector. I think even with a 22% resistance the module should still be able to make the connection. But I will splice a new wire from just outside the control module plug to the just outside the pump motor connector. Maybe eliminating that 22% resistance will make the difference. Time will tell.

 

Have you tested the relays themselves? One or both might be more useful as a paperweight now if it has failed. You can do this in many different ways:

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FIRST: Switch the ignition key off, unplug the relay from its electrical connector. Then identify the relay's power and control terminals. Some relays show a circuit diagram on top or side of the case to identify these terminals.

1. Check for continuity between the two power terminals using an ohmmeter. There should be no continuity. If there is continuity, replace the relay.

2. Connect a jumper wire between the battery positive terminal and one of the control circuit terminals on the relay. Connect the other control terminal to ground with another jumper wire. If you do not hear a click as you make the second connection, reverse the connections. If you still do not hear a click, replace the relay.

3. Connect the jumper wires as you did above. Using an ohmmeter, check for continuity between the two power terminals. If there is continuity, the relay is working properly. Otherwise, replace the relay.

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Any amount of resistance can cause unknown problems. Too much resistance and the full voltage is unable to pass through. Too little resistance and you can end up with a fried component. But seeing as you just did an end-to-end test of the wire and there are no loads between the two meter probes you should be getting a low voltage reading.

Hold the meter's probes on top of each other firmly while on the 200 or 2K Ohms scale and see what the reading is. If that reading matches the resistance of the wire you did the end-to-end on then that wire is fine.

Go ahead and make a jumper wire for the wire going to the pump motor but do not cut the existing wire just in case you find the problem to be the entire wire. There are a couple ways of jumping a wire using what's already there. The way i usually do it includes putting 2 small holes in the existing wire's insulation and plugging in my jumper using the holes. But test the relays before you go through all that trouble. It sounds like you may have broken or frayed wire leading to the pump motor but the relays are far easier to test and are more likely to have gone bad than the wire itself.

 

Before trying to splice in a wire to bypass the resistance in the wire, I retried testing the continuity this morning. Looking more closely at the provided wiring diagram I see that there are TWO Tan/Red wires. One is for the pump motor and the other is for the rear dump valve. Well, tried the continuity on the "other" Tan/Red wire and zero resistance.

Will test the new relays I installed.

In the mean time I contacted the company that refurbished the control module to see about getting another replacement.

 

Ok with a 0.00 resistance reading on that wire it's telling me that the wire is broken somewhere in the circuit. You should have atleast received the resistance of the meter's probes back but seeing as you didn't that's a good indication of an open circuit. See if you can trace the entire length of the wire looking for any breaks in it as you go along. OR do the jumper wire test on that wire and see what happens. A broken wire would not allow for the voltage sent out by the meter to return to the meter which would give you a 0.00 resistance reading.

How did the test on the relays turn out?

Any luck with the company on receiving a different module?

 

When I say zero resistance...if I set the meter on the 20k setting the meter reading starts at 10.000 and touching the probes together sees the numbers drop to 0.000. The same hold true when testing the continuity of the wires. I get the same reading for the wires as I get when touching the probes together.

Tested the new relays and they are fine also.

Just waiting for a response from SMP (Standard Motor Products) the supplier of the refurbished ABS control module.

In the mean time a piece of electrical tape over the ABS light makes driving a bit less irritable.

 

Ahh ok then if that's happening when doing the end-to-end test on those wires that indicates a good wire.

Seeing as the wires are all good and you have no short to grounds it's seeming more and more likely that the problem lies with the control module. Just keep at it with SMP and should receive a "new" control module.

Keep us updated

 

SOLVED!!!

Out of frustration,I decided to check all the wires associate with the ABS system NOT directly inline from the Control Module to the Pump Motor. One of the wires was from the engine compartment main fuse relay box to one of the two associated ABS relays in box #3.

To trace the wires colors, I had to remove the main relay box and box #3 to flip them upside down. In flipping the main relay box over, I noticed a bulge about 1/4" long and 1/2" away from the underside of the box for the yellow/green wire. Did a continuity test from the associated 30A main fuse to the relay and no continuity. I cut the wire open and a bluish green power (copper corrosion) came out about the length of an 1/8". The rest of the wire was clean but completely severed. Spliced a wire in its place and lo and behold the ABS light disappeared.

The wire had to be pinched at the factory during installation. It was too well protected.

Finally slept good last night. Called SMP this morning and let them know too.

 

Well there was a great a idea that just happened to solve your problem. Glad you got it fixed! This type of thing doesn't happen very often (atleast that I'm aware of) but certainly can. Again, glad you got things sorted out!