gracer7-rx7

iTrader: (16)

@Mike93r1 and @Perpetual
https://www.rx7club.com/members/2mchpwr-51388/
I remember this guy going through hell trying to figure out ABS issues. Might want to review some of his posts. He actually bought the factory tool to figure his issues out and resold it. Good luck.

Perpetual

Thank you for the head's up. Might have to go the same route, everything is testing "within spec" so far. Frustrating.

gracer7-rx7

iTrader: (16)

Yep. You can probably find ABS parts from part outs in the Marketplace section of the forum if you decide to go that route. Good luck! The ABS system rarely seems to break so there isn't a lot of historical threads on it.

Molotovman

iTrader: (49)

Has anyone ever serviced the front or rear knuckles and removed the ABS sensors? They are pretty sensitive and if they are slightly out of alignment due to a partial crush or bent tab from removal they will cause the light to come on.

Perpetual

I had to reassemble the entire front of the car upon purchase to drive it home. ABS light was on at that time but wasn't causing drivability issues until I had to stop quickly. Front passenger wheel locked up. After a quick search, found that the abs sensor was not plugged in at all. The light did not go out after reconnecting. The sensor tests within ohm spec on two different multimeters, identical to the front driver's side. All the associated fuses are good.

Next will be testing the relays per the FSM, and the contacts in each connection for corrosion/burnouts.

I'm just trying to do everything possible before throwing $$ at an ABS tester that may not be operational (all sale final situation).

Perpetual

As far as the alignment of the magnet to the ABS ring, would anyone be able to snap a picture of proper alignment/gap?

MarcZ55

Just had ABS light come on last week. Right after I changed the oil filter pedestal o-rings.
Light only came on once starting moving about 5+mph.

First thought was an abs speed sensor. I had it on a quickjack so I tried to spin the wheels to trigger the light to possibly isolate but no luck. Probably wasn't enough speed. Went to visual inspect passenger abs sensor connector and sensor. As I'm looking I see rat poop 🤦‍♂️. Didn't see evidence of chewing or broken wires on that side, sensor & rotor teeth look good. Didn't Chek resistance yet, then moved on to driver side abs connector. And sure enough more rat poop and after moving cruise control actuator out of the way, I see broken/chewed wires. 3 wires, 2 to the abs connector and pink wire that not sure exactly went to but looked like it was part of loom going to fuse block.

I knew that was the culprit. Damn rat. Pulled fender liner out and was able to pull the wiring down threw wheel well. Made all necessary fixes, some soldering in a couple areas, heat shrink, heat shrink wire connectors and bunch of electrical tape.

took it for long drive and no light.

Im guessing I would have had to check continuity or voltage at the abs ecu had it not been visible. It was on that side of the connector/wiring.

MarcZ55

Pic of damage

coupe-r

For anyone reading, this is NOT how to test the DIODE! The manual states check for continuity which is a bit misleading.

Use a multi-meter with diode test ability ideally, it should only show a voltage drop ranging from 0.5 to 0.8 volts (and only if you have the leads hooked up in the correct direction.
If trying to check for resistance of the diode, (again only will show resistance in one direction) its MORE like 6 MEGA OHMS not 660ohms...
resistance of a good diode should range from 1000 Ω to 10 MΩ.

Couldn't help myself but correct this info as I bet people pulling diodes out for no reason..

ptrhahn

iTrader: (9)

Hey all,
I've discovered I have non-working ABS. Nothing obvious, fuses appear good, nothing in the module LOOKS fried, but I have an aftermarket dash, and thus can't discern ABS light behavior. Is there another way to diagnose?

I haven't checked the rear wiper fuse under the dash, its sort of tough to get at, can anyone confirm whether that being bad simply trips the light, or would cause ABS not to work?