Ford Rabs Valve Diagram Wiring Circuit
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Discussion Starter · #1 ·
My RABS and brake light stays on, pulled codes (11) and got a 4 for the RABS, using Steves info a code 4 is "Rabs valve switch closed". Brakes seem to be working fine, fluid is full. Any ideas where to go from here? My Haynes doesnt go into the RAB valve switch.
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Discussion Starter · #2 ·
Steve, I read your diagrams, I can't see where it says How to test the switch or where the switch is.
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Service manual says if yellow antilock and red brake light are on, you need to check:
1. master cylinder brake fluid level
2. master cylinder float for buoyancy
3. check for proper functioning of the diode/resistor element
4. obtain the flashout code
(4 flashes = RABS Valve Switch Closed)
a. check RABS valve harness connector with ohmmeter
b. check RABS module harness connector
5. check proper functioning of the master cylinder fluid level indicator switch
6. check for shorts in brake light wiring
This is covered in about 6 pages of the factory service manual. Have you done all the preliminary checks? I don't have my camera now to copy all the pages. Let me know exactly what you need and I'll look it up. I'm looking at the 1988 factory service manual and I assume it is the same for 1990.
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Discussion Starter · #4 ·
Thanks guys, I can read a wiring diagram (do a good amount of control wiring at work) , everything I work on is usually AC. DC wiring always screws me up, looking at the diagram Steve posted, the only "switch" I see in the RABS Valve is the reset switch. If I measure resistance between the LB/R wire and ground and have no resistance I know the switch is closed but what does that tell me?
I really need to get the service manual for my truck, Haynes just dont cut it. Does the service manual go into extreme detail? Like, have the key in whatever position, test pin whatever to pin whatever, if you have this amount of resistance then the sensor is bad.
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A factory service manual helps a lot.
Here are some pages which may help you.
RABS components
RABS component location
RABS diagnosis and testing
Diagnosis charts
Flashcode 4 page 1
Flashcode 4 page 2
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Discussion Starter · #6 ·
I guess I need to replace the valve, when I test from the switch pin to the body of the valve I get 2.55, 3.5, 1.2, and .9, no idea why the values keep going down but they are no where near 10k.
When I test from the valve solenoid ground to the switch pin I have an open cicuit (OL).
Ive never used the dealer manuals, how accurate are they usually? If they manual says to replace something are they mostly correct?
Source: https://www.fullsizebronco.com/threads/rabs-and-brake-light-on-pulled-codes-now.103542/
Posted by: fitathomeand.blogspot.com
