ABS Light On: Troubleshooting & Fixes

Hello.

I'm having the following problem with my Golf IV TDI, manufactured in 1998.

When I turn on the ignition, the ABS warning light illuminates.
and it illuminates again after the self-test, as it should.

However, when I start driving and exceed 20 km/h, the light turns on.
It's no longer working.

I had the error memory read, and it contained the following:
Error: 01276 016
Hydraulic pump ABS-V64.
Signal outside of tolerance.
intermittent error
sporadic error
occasional error

At the VW dealership, they told me I would have to...
Replacing the complete hydraulic unit, including the control unit, costs approximately 800 euros.

I then bought one from a car that had been in an accident.
However, after installation, it caused exactly the same error.

Has anyone else ever experienced this problem?
Could a wheel sensor be causing the error, even though there's nothing in the error memory?
'None of this is true/accurate/correct.'
Is there a way to test the wheel speed sensor for functionality? (Can it be measured?)


I would be grateful for any helpful advice.

Best regards,
Andreas

Such a search function is really a great thing...


The error may be caused by the following reasons:

Interruption, short circuit to positive or in the wiring.
Internal connection from the hydraulic pump V64 to the control unit.
Hydraulic pump V64 is defective.
ABS control unit J104 defective.

Since you are still experiencing the problem even after the exchange, I would like to...
Get the wiring diagram and start troubleshooting. If there's a problem with the sensors, it will 99% of the time also result in an error message. So, first look for the most obvious causes...

aprr wrote:

Is there a way to test the wheel speed sensor

for functionality? (Can it be } measured?)
Hi Andreas,

Use VAGCOM to access the ABS system. There's a measurement block that displays values from individual sensors, each showing a speed reading in km/h.
Ideally, they should all report the same value during normal straight-line driving (assuming the tires have the same circumference) - if not, there's likely a problem with the sensor.

I'm having the same problem, and I've already had a new control unit installed (at the suggestion of my Skoda dealer), but the problem persists! None of the tips you mentioned above have helped me. Now, Skoda wants to replace the wheel sensors, even though they're not showing any error messages (it's just a suspicion from Skoda), but the cost is outrageous!
Perhaps someone among you has the wiring diagram for the ABS system, or any other helpful tips.

Best regards,
Matthias

Hello!!!!! Ulf described it perfectly: connect the VAG Com, start the car, and check what values the sensors are reporting. If three values are the same and one is different, that's a starting point for troubleshooting. A workshop that randomly replaces the wheel sensors without proper diagnosis should probably be given a bottle of brake cleaner and asked to clean the sensor discs. These sensors are durable, provided no one has tampered with them. Next, you can start looking for cable breaks. But even then, the VAG Com can save you time.

Thanks for the tip, but all the signals are the same. The pump is directly controlled by the control unit, and there's no power coming from that unit. The pump itself is working fine!
When does the pump need to be activated? I can drive 10km or more while staying below 20km/h without the ABS light illuminating, but as soon as I reach 21km/h, the light comes on and only turns off after switching off the ignition. I'm at a loss because VAGCOM shows the same error message as described.
I'm open to any ideas.
Thank you in advance.

Best regards,
Matthias

Hello.

I've recently been experiencing the same problem, and I wanted to ask if you've managed to resolve it and what the cause was? Thanks.

Best regards, Günni.

Even with the risk of getting hit .

'Can't you also use VAG-COM to perform an ABS actuator test for each individual wheel (please only while stationary)? In conjunction with the km/h readings, as mentioned by Ulf, you can almost completely rule out wiring issues. Or am I wrong about this?'

Unless you have an intermittent cable problem (a loose connection...), and it's not occurring right now when you're measuring.

@ AndreasG

I don't think it's the sensors.

@all

My error is the one described above, 01276 hydraulic pump ABS-V64, and it's not appearing sporadically. You can run an actuator diagnosis with the pump, and after the error is cleared, it reappears immediately after the actuator diagnosis. When driving, the self-test seems to only run at 20 km/h, and even then, the error is immediately detected and displayed. As far as I know, the sensors can only be diagnosed electrically when the vehicle is stationary, but their functionality can only be tested when the wheels are turning. However, I'm not getting a sensor error code.

I actually wanted to replace the hydraulic unit, but I've read a few times that it didn't fix the problem for some people. I'll also take another look at the wiring this weekend. My hope was that someone might have already solved this problem and could give me a tip.

Thank you very much for the answers. I am still grateful for any suggestions you may have.

Best regards, Günni.

Okay, here's what comes to mind: When I use VAG-COM to test, the individual sensor readings for all four wheels work up to 20 km/h, as long as they are all the same (please have a passenger take the measurements). If they are equal at that speed, the sensors and cables can be ruled out. However, above 20 km/h, VAG-COM stops working, and that's when your problem starts. It might be that the software code is incorrect. Unfortunately, I can't think of anything else right now.

Hello!

This might not be helpful, but I had the same problem not long ago!
It was due to a faulty ABS sensor on the front left.
However, my troubleshooting was a bit easier, as the sensor had a very small crack.

Best regards,

Olli.

'To everyone, thank you for your help so far. aprr also contacted me, and the error disappeared on his system after 8 months. However, I don't want to wait that long or rely on that happening.'

@roli752001
It can't be due to the VAGCOM system, because I read the error memory and performed actuator tests using a V.A.G. 1552 device.

@aewpctd
Did you have the described error 01276 Hydraulic pump ABS-V64 in the error memory, despite a fault in the sensors? If that was the case, I would definitely need to look more closely at my sensors.

Best regards, Günni.

"On my G III, the ABS ribbon sensor had a problem. It was corroded. Occasionally, after a cold start, the ABS warning light would come on around 20 km/h. I couldn't read any error codes back then, but after proactively replacing the ribbon sensor and cleaning the connections, the problem never occurred again."

Hello!

@günni812


Unfortunately, I'm not yet able to read the error codes. I ordered a diagnostic adapter from 'Die Diesel Schrauber' the day before yesterday, and it shipped out today.
Then I'll know more, and there might still be a bug that hasn't been fixed yet, since it hasn't been that long.

Best regards,

Olli.

@ all

Today, I thoroughly examined the car again and measured everything. All connections (power lines, both positive and negative, for the pump, valve block, lines to the wheel sensors, and control unit) and components (pump motor, wheel sensors, control unit, etc.) are in good condition. I couldn't find any faults. All lines are transmitting the correct voltages and signals. All components have the correct resistance values.

Completely desperate, I followed the advice of Roger and checked the fuses again, measuring them. Everything was fine there as well. Nevertheless, I cleaned the contacts of the fuse holder and replaced the fuse.

And lo, it works again . Apparently, a tiny layer of corrosion on the contacts was enough to prevent the current from flowing through the fuse when the pump started, and the control unit recognized this as a defective pump.

So, thank you again to everyone. And if the light ever turns on, then immediately check the fuse .

Best regards, Günni.