Hello: I am baffled by this:
Truck is 1997 F-150 4x2 XL long bed with RABS. Last time the lights came on, I replaced the following: Sensor on differential;ABS module (underneath the master cylinder; master cylinder. one at a time and after replacing the ABS module the problem went away for about 8 months. Both lights are ON again since this afternoon. So what should I do now? start over from sensor and work my way back to ABS module that is located underneath the MC in engine compartment? Please help.

Thanks
msk

 

You really need to read the code. I think all DIY'ers need to invest in a scanner. Without it, it's a guessing game. I solved ABS/Brake (both yellow and red lights) problem with a scanner, and saved the cost of scanner.

One thing you may want to check is the voltage drop between alternator output post and battery +, and alternator case and battery -. You got nothing to lose.

 

I did previously. It was 4. The way I checked it by grounding the orange or red wire on the passenger side kick panel to ground and counting the number of blinks on ABS light.

As you know that this code does not show on the usual check engine light code.BTW, I do have a scanner that is installed on my truck called Kiwi MPG. however, besides other stuff, it also reads and clear the codes. and I do not see any code.

I am told that ABS and brake codes are not registered on the Check engine.

msk

 

You are correct. When I got ABS and brake lights on, my Actron scanner read no codes. I bought a more expensive scanner and it read both codes. A decent scanner costs about $150 and it reads ABS, body codes, manufacturer specific codes, bidirectional communication, etc. Maintaining a 97 can become very expensive if the vehicle is taken to a shop for every malfunction. It is hind sight but had you bought a scanner, you would not have replaced ABS module. Even a jy part costs about $30.

 

I am in the market for a decent scanner and can spend some doe. Do you have any in mind that are decent.What about the one you have?

BTW, the module was like 45 shipped used from someone on the forum.

 

A 1997 RABS system doesn't need a scanner to pull the codes. You can also read the ABS codes exactly as msk59 indicated.

 

I thought that was case. Anyhow, the issue is there and I need help. If someone else was succeeded in doing something else then what I did then please share with me.

Thanks

 

What is the code? 004? What letter do ABS codes start with? I will look up my shop manual for you.

 

Read the codes and follow the diagnostics to see what's going on.

 

the way I understood to read the code is this: Ground the wire and turn the ignition ON. Then count the number of times the ABS lights blinks. It blinks 4 times then pause and then another 4 times. so the code is 4. Last time the code was 4 and after I replaced the ABS module that is located underneath the brake master cylinder, the code went away for about 6 months or so.

 

Don't care at the moment what happened 6 months ago. You have to read the code that is currently stored in order to diagnose whatever is wrong now.

 

LOL thanks, I will re-read the code and post for suggestions. I just need to find time to concentrate on the issue at hand.

thank you.

 

OK read the code and it is 12. The light flashes 12 times. Now is it the bad antilock electronic control module this time or circut 511? I could not go any further than that.

 

LFC 12 means:

Low master cylinder fill level.
Fluid leaks in vehicle brake system.
Brake fluid level warning switch (2L414).
Master cylinder float.
Diode/resistor element in stoplamp circuit.
Ignition switch.
Ground short in circuits 512 (T/LG) or 531 (DG/Y).
Anti-lock electronic control module.

There is a complete diagnostic procedure in the service manual.

 

Hello ProjectSHO89: Thanks: I got the factory manual yesterday and ran the diagnostic procedure only about to either short in circuts 531 LG or Anti lock electronic module, Found and ordered the anti-Lock electronic control module from an ebay (new) for this vehicle, just in case it is bad so I do not have to wait for the it longer. My guess is it is this that has failed. I will post results next week when I replace the module.

thank you for your help and guidence.