Intermittent ABS code 53. 5th Gen BB8

[mercutio]

there is a connector just behind the centre console on the drivers side

[prelerepairman]

it would eventually depends on how much water has been absorbed i suppose i am only surmising the unit is designed to live in the engine bay so will be used to heat mine gets hotter than a standard one would because of my manifold but i dont have that issue.
So either your Abs module is affected in some way that mine isnt or something is affecting it internally ie fluid.

when you wrap it you havnt noticed any dodgy wiring have you?

I have swapped all wires and cleaned all oil and gunge,..did think heat might be swelling a broken wire but that's really unlikely.
My assumption is that these newer -post 1977-abs units =without the old pressurised globe underneath- also have the 2 opposed pistons on an eccentric motor shaft and that , just like the ones on Gen4 'Ludes, the "pistons" are swollen or dirty or tight and therefore when heated the unit expands and the pistons start to move. This is purely an assumption as I can't find info on the internals and don't want to take mine to bits. All I can be certain of is that heat and low airflow fixes the problem.
I'm simply going to bleed my brakes as suggested above. Will update here.

[prelerepairman]

there is a connector just behind the centre console on the drivers side

On my British Gen5 the blue 2 pin connector is just above ankle height, on the right hand side of passenger (nearside) footwell behind a wee 4 inch square..ish pull off piece of carpet!

[wurlycorner]

That's how you get the fault codes.
Surely you must have done that repairman, otherwise you wouldn't know you have code 53?

Its GJM thats asking @wurlycorner

Oh yep.

I've done a merc and cocked up while speed reading...

[mercutio]

That's how you get the fault codes.
Surely you must have done that repairman, otherwise you wouldn't know you have code 53?

Its GJM thats asking @wurlycorner

Oh yep.

I've done a merc and cocked up while speed reading...

kebab

[vtijon]

Check pump motor resistance and carry out a continuity check between pump motor connector and battery earth terminal. The ABS ECU motor check line tees into the pump motor feed and gets an earth through the motor when the motor isn’t running and no earth when the motor is running to tell the ECU the pump health. High resistance through pump motor winding's or pump earth will cause the ECU to think motor is running when it shouldn’t be and ECU will shut down ABS and light comes on. On engine start up and throughout journey ECU will run pump to do a health check. The motor won’t always stop at the same point on its internal contacts so you could have different resistance each time pump is run confusing the ECU. The pumps are the opposing type because I’ve removed motor on one unit and then motor won’t go back in because pumps have sprung out. When I got a replacement pump for my car I gave the motor several short tests on a battery and checked resistance each time which at every stop position was 0.5ohms.

[prelerepairman]

I shall check resistance.thanks, and replace brake fluid using a pump system (advised to avoid overstressing the old master cylinder !)
I have tested the car for 2 weeks now and the ABS light problem is definitely not random..apologies for that!
If engine is hot and stationary the ABS light goes off and code 53 disappears. If I then drive at 30/40 mph light stays off. If I go up to 70mph the light will come back on (after a short time) unless I place a rag or other insulation in front of ABS pump carefully avoiding snagging the belts and pulleys!!!!
If car hot and parked, the fault can be gone for up to 4 hours.

[prelerepairman]

I'll keep this going incase someone else has similar prob:
Mot tester did something which caused abs light to come on a nd remain on forever...probably stomped the brakes. Handbrake failed mot. So serviced both rear calipers and replaced pads . Syphoned the old fluid out of fluid reservoir and flushed the system (not front calipers yet.....jobby weather and no garage).Abs light went off and stayed off....for a few days. Back to previous condition: when engine hot and left standing for 20 mins the light goes off for 3 hours or so (out of town driving brings it on quicker-cooling airflow again I guess). Anyway back to exhaust problems first.