ABS light on with no DTC(s) ??

[seafish]

The ABS light on my 2005 4x4 has been lit in my truck for awhile now.
It happened out of the blue and I have not paid attention to it becuase I am no fan of ABS systems and there seem to be no braking problems with the truck.

I finally got around to checking the DTC with a Smarty POD code reader, and there are none.

I am fairly sure that if an ABS sensor was damaged or broken , it would set a DTC so I am looking for an informed explanation of why the ABS warning light remains lit with no DTC and why I cannot reset it with the Smarty, which should be able to do so.


TIA

 

[seafish]

OK slightly embarrassed, cuz after reading the Smarty manual for he first time in many years, I now realize that it CANNOT read ABS codes but can reset the ABS light.

I have properly attempted to reset the ABS and brake light twice now, but to no avail, they both remain lit depsite erasing all codes.

Is this is simple as one or more ABS sensors gone bad so that it comes right back even after has erased it ??

ALSO, are the ABS sensors testable with a DVM resistance reading??

TIA

 

[Yo Hoot]

When my ABS light came on, it was the clockspring in the steering wheel. Common issue.

Here's a video I did...

 

[seafish]

And did that include the parking brake light being on as well??

 

[Topzide]

Time to get a reader that does ABS. That way, you'll know what sensor has failed. Without knowing if a sensor, or clock spring like @Yo Hoot mentions, you'll be beating you're head on the dash! Good luck with issues.

 

[Yo Hoot]

Does your truck have steering wheel radio controls and do they work?

I had a guy that is in business for himself who used to be a tech at major dealerships. He has a van loaded with all his diagnostics equipment. He stopped over and tied into my truck via bluetooth. With his system he said it showed a disconnect somewhere in the ABS wiring. I replaced the clockspring and the fault went away.
The clockspring has a ribbon cable inside that is designed to fold and unfold as you turn your steering. The fault was right where the ribbon terminates to it's connection. The internal power strips in the ribbon failed there from constant flexing.

If you go towards the end of the video I posted you'll see where I took the old clockspring apart and showed the place that was damaged.

 

[Ozymandias]

Diagnose it properly before spending any money.

 

[seafish]

Diagnose it properly before spending any money.

Yes that is eaxactly what I am trying to do by asking questions
Heres another one —

Will the key on/off/on procedure read ABS codes??

 

[seafish]

Does your truck have steering wheel radio controls and do they work?

No radio controls on the steering wheel, though all the cruise control still work fine.

I DO have to track down a broken or breaking wire in the drivers side door that is intermittently throwing instrument cluster codes, thought Im not sure how that would have anything to do with the ABS light.

I'll post back what I find after pulling up the DTCs with the key trick as opposed to the smart reader.

 

[sag2]

You need a scanner to read ABS codes. The cluster will not display them. Harbor Freight sells them for under $100, especially if you wait for a sale.

 

[Yo Hoot]

Looking forward to seeing the results

 

[seafish]

You need a scanner to read ABS codes. The cluster will not display them. Harbor Freight sells them for under $100, especially if you wait for a sale.

Key on/off x 3 brought up one code (P0483) for fan control circuit error and nothing else.

Cluster check codes gave me —

67 95 ( intermittent short in the drivers door wiring)
68 01 (same as above)
A3 38 (battery disconnected while working on her)
A4 12 (unknown but non worrisome problem with ignition / start circuit)

A7 24 (VIN checksum error and REALLY hoping it has to do with Smarty)

AA 24 (this code is unkown to me so, PLEASE chime in

SO looks like I'll have to recheck for ABS DTCs once I get my other decent aftermarket scanner back from the person who borrowed it.

 

[seafish]

OK so diving deeper into the AA and A7 codes, they are each set the exact same number of times, so likely related top each other, though NOT necessarily to the ABS light being on.
ALSO somewhat noteworthy is that the A4 error is exactly half the incident count of those two codes.

BUT I have a PLAN!!!

Seeing as how the AA and A7 are related to PCM and VIN checksum errors, I am wildly guessing that they MIGHT be related to how many times I have used Smarty over the life of the truck and that BOTH those C code communication errors MIGHT be related to those programming events.

ALSO, I am thinking that I havent been previously able to connect to the trucks EU with the inexpensive but well reviewed code reader that I have, even though it connects and works well with all my other, and my friends other, vehicles … I am THINKING that might have to do with it NOT recognizing the Smarty POD software.

I SURE do wish that Bob Wagner was still here and could answer these quesitons for me!!!

Either way, I have the code reader back now, and tomorrow, I will use Smarty to reset the truck to stock parameters and programming and then directly after I will

1) Check to see if the AA and A4 errors increase by one count, thus telling me that I am correct in my wild guesses.

2) Use the code reader to check for ABS codes, thus telling me that I was right about it being confused by Smarty and also HOPEFULLY telling me which, if any, of the ABS sensors are bad.

NOT sure if its a good plan, but it IS a working plan with minimal downsides…I'll keep that batteries on the trickle charger while doing all the programming and code checking

 

[Ozymandias]

Yes that is eaxactly what I am trying to do by asking questions
Heres another one —

Will the key on/off/on procedure read ABS codes??

No it won't, you need a Snap-on, AutoEnginuity or wiTech.

 

[seafish]

Unfortunately, while the Amazon code reader I bought is a decent one, it still doesnt read ABS codes.

So instead, over the weekend, I removed the front wheels, disconnected the sensor plugs and checked resistance on the sensor side of the plug

Left side read around 1.8k ohms but the right side read as an open circuit.

Found a Mopar ABS sensor on Rockauto, and was about to pull the lever on it for $63 but I was a little unclear as to whether it was the rear speed sensor or the one I needed for 4wd front.

So I went back after dinner to try to figure it out and, by then, a single Standard Motor Products for the front 4wd ABS sensor came up as a closeout for $14 plus 6$ shipping.

I have used SMP ignition and sensor products on my other vehicles with solid success so I am hoping that this one will be a good match and for that pricing I couldn't really pass it up.

 

[Grumpy8811]

Unfortunately, while the Amazon code reader I bought is a decent one, it still doesnt read ABS codes.

So instead, over the weekend, I removed the front wheels, disconnected the sensor plugs and checked resistance on the sensor side of the plug

Left side read around 1.8k ohms but the right side read as an open circuit.

Found a Mopar ABS sensor on Rockauto, and was about to pull the lever on it for $63 but I was a little unclear as to whether it was the rear speed sensor or the one I needed for 4wd front.

.

you need a scan tool that has ABS functions.
I had an ABS problem, had a bad wheel speed sensor.
purchased the Standard motor parts brand part at O Reilly and afterwards had intermittent wheel speed sensor issues for months, they would come and go.


finally I had a revelation and thought maybe just maybe the non OEM wheel speed sensor is the problem so I bought the Mopar sensor from a dealer.

Problem fixed.. just like that.

 

[Topzide]

I've used many non OEM ABS sensors over the years on many vehicles. Never had an issue! I always make sure that connection is tight with dielectric grease in the connections. I'm sure that there may have been another issue or you could have gotten a faulty sensor. When making a sensor such as an ABS sensor, it either works, or doesn't. Theses sensors are simply a magnet that senses metal from tone ring. Easy to confirm that it works. I've used OEM replacement parts that have given me issues, so not just an aftermarket thing. That's why we have choices, and choose which one you'd like to use.

I believe that you like to use the "cheapest" oil filter on sale for your CTD. That's your choice. Glad that you've had success with them. Not my choice. Testing and diagnosing the issue, rather than the parts cannon, is better!

 

[Yo Hoot]

you need a scan tool that has ABS functions.
I had an ABS problem, had a bad wheel speed sensor.
purchased the Standard motor parts brand part at O Reilly and afterwards had intermittent wheel speed sensor issues for months, they would come and go.


finally I had a revelation and thought maybe just maybe the non OEM wheel speed sensor is the problem so I bought the Mopar sensor from a dealer.

Problem fixed.. just like that.

Could be a sign of your unit bearing going south. When they go bad they touch the sensor and short it out.

 

[Ozymandias]

Just found out that Autel/ Launch X431 can read it all. But also 550$ around.

 

[Grumpy8811]

Could be a sign of your unit bearing going south. When they go bad they touch the sensor and short it out.

not in my case, the fix was 4 years ago.