I have a 98 E-250 rear wheel ABS only.. The ABS light is staying on.. I pulled a code 77..... 7 flash and 7 flash... What is that ? never seen it before and how to fix it

 

Not sure this will be helpful but according to the Actron DTC site, entering your chassis and year I could up with a "No Isolation Solenoid During Self-Check".

HTH

 

No that did not work. The codes they have only go to 16

 

I'm assuming--maybe incorrectly?---you have OBD-II which should be able to be easily interrogated by most hand-held scanners. My '00 and '03 E250's DTC's are easily read and interpreted by an Actron scanner---have you tired one of those yet?

I wonder if you might get more in-depth answers posing this same situation in the Brakes & Chassis forum?

 

'98 should have OBD-II system, which would give you a 3 digit code, from a scanner.

The rear only ABS is an isolated controller, mounted on the passenger side, lower dash (interior) behind the knee panel.

This controller is indirectly connected to the PCM, and you might not pull a code thru the OBD-II reading.

The brake controller can be replaced, but very expensive.

There is a scanner that is only for the brake controller, that can clear any store codes, taking the yellow ABS light off, a good brake shop, or repair shop should have this scanner on hand.

First find the source why the light came on, like a leaking brake line, faulty wheel sensor (speed sensor) then you can clear the code. Sometimes, replacing the speed sensor, will also cancel the warning light.

Also, there is a post in FTE on removing the spring in the ABS unit that will restore a soft pedal, and turn the light off, it worked for my '92 E350.

 

on my 98 I have a wire that you disconnect that is on the passenger side of the dash... Black/orange. You ground the black orange temporarily and it gives the code by way of ABS dash light. It is most definitely a code 77

 

We're not doubting your code but this sounds like an OBD-1 system which would have been early years OR perhaps an E350?

Very confusing this is---sorry I can't be of more help. I will suggest looking up that code for the OBD-I system, see if it relates or is helpful.

 

Ford's OBD-I is the Ecc system which would read out a 3 digit code.

Any vehicle from '96+ would have the OBD-II codes.

I did some searching and found this article which sounds similar to your problem -

https://www.ford-trucks.com/forums/1...abs-light.html

Again, it relies on a separate code reader for ABS controllers.

Quick tip - take a ride, keep an eye on the speed-o needle, if it' bounces around at 30-40mph, the wheel sensor on the top of the differential is in need of replacing, and that also effects the ABS sensor.

 

The RABS (rear antilock brake system) cannot be read by any scanner. The self test is to ground the black/orange wire and count the ABS light flashes. This system uses codes up to 16, and repeats them. Code 7 leads to Anti-lock electronic control module fuse blown or internal open circuit.
Shorted isolation solenoid internal to the RABS valve.
Intermittent short or shorted circuit in Circuit 599 (PK/LG).
Contamination or bent Pins 1 and 3 of RABS valve connector shorting together.