P38A ABS Fault on Dash, Nothing on Nanocom?

Hi. Searched and searched but can't find an answer for this specific fault.
When servicing the car a week or so ago, it looked to me that the Brake Fluid reservoir was over full, so siphoned a bit out. After I'd finished service and started the engine, LOW brake fluid light came on with ABS light.
Double checked reservoir and realised I'd been looking at an old stain on the side, so topped it back up to the correct mark. LOW warning went out.
But ever since then the ABS light stays on all the while even when driving, and it flags up ABS Fault on the dash, when first started up. But when I plug Nanocom in ut says No Faults? Sometimes it says, "error, unable to start communication with ecu" but after a few goesit usually reads ok, shows the settings and inputs etc, but still says No faults found?
Any ideas please?
cheers.

Check all ABS sensors are pushed all the way in.

Given the fluid dropped low you might have let air in. That modulator hates air so brake bleed might be worth a go.

@supapete had exactly the same issue, turned out to be a dicky plug connecting one of the abs sensors and also, there is a steel casing around the hubs which can be misaligned thus not allowing the sensors to go all the way in.
With both of those corrected he's sorted now.

try adjusting the brake light switch on the pedal

You check the fluid level once the pump has finished running otherwise it will show as over full

Fluid level is checked when the pump has stopped running. I would guess you have introduced air into the system and a complete as per RAVE brake bleed is in order.

Thanks for all replies.
I’ll have a look at it again when I’m next off work.
Cheers.

If it’s stained in there, fluid may be old anyhow.

RangeRoller dt said:

If it’s stained in there, fluid may be old anyhow.

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My fluid is brand new but mine's stained badly. Another job to do!

I can hardly see through mine, I measure from top to the fluid, then transfer the measurement outside to see where level
Is. My accumulator runs more since I cocked it up and needs few pumps first thing.
Can’t work out what changed or is wrong? But it works.

Brakes are spot on, but ever since i bought it the accumulator seems to come on every time I press brake pedal when car is stationary. Hard to tell at its doing when car is moving.
Will change fluid etc at weekend and see what happens.

Check your abs sensors first

BrenK said:

Brakes are spot on, but ever since i bought it the accumulator seems to come on every time I press brake pedal when car is stationary. Hard to tell at its doing when car is moving.
Will change fluid etc at weekend and see what happens.

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so the accumulator needs replacing?

I had multiple issues, accumulator needed replaced and also the reluctor ring split so did the accumulator first (as it was the worst) the changed the CV joint and all is well. Superb in fact

Accumulator sphere was around £100.
CV joint was about £25.

Both easy jobs.

Datatek said:

so the accumulator needs replacing?

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Thats why i mentioned it, as I don't know what its supposed to do? Does it need changing then? If so I'll do it.

BrenK said:

Thats why i mentioned it, as I don't know what its supposed to do? Does it need changing then? If so I'll do it.

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Turn off ign, pump brake pedal several times to diminish any stored pressure, then switch ign on. The pump should run for approx 10 seconds. Any longer and your accumulator sphere has lost it's ability to store pressure. Press the brake pedal and let go, does the pump start immediately? If so, again, the sphere is knackered.

10 seconds sounds a bit optimistic, mine runs for 30-40 seconds when all the pressure has drained. Then runs for a couple of seconds every fourth press of the pedal

kermit_rr said:

10 seconds sounds a bit optimistic, mine runs for 30-40 seconds when all the pressure has drained. Then runs for a couple of seconds every fourth press of the pedal

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Since replacing the sphere, Mine runs for around 10 seconds and about every 8th press....

They wear slowly so you tend not to notice until they are on the bones of their arse I suppose.

Doo said:

Since replacing the sphere, Mine runs for around 10 seconds and about every 8th press....

They wear slowly so you tend not to notice until they are on the bones of their arse I suppose.

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Interesting! Mines been 30 seconds since i replaced the accumulator

kermit_rr said:

Interesting! Mines been 30 seconds since i replaced the accumulator

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Is that 1st thing in the morning or in general?

I suspect mine may run a bit longer in the morning, but during the day it's short runs.