sl55amg TPC faults

Alex Crow

Senior Member
hello peoples, how you are.

we have a beautiful SL55AMG in at the moment with the beru tyre pressure monitoring. it came to us unable to initialise and warning 'visit workshop' - like they do. with the aid of star we found 1x sensor not working and 1x sensor beyond it's programmed service life. on changing the sensors it initialised ok and mr nice customer went away happy. sadly only a week or two later he was back with the 'visit workshop' display, but the pressures still displaying in the instruments. the only logged fault code is B1344 - check component A69/1 (left front sensor), stored and current.

the first thing we did was take advantage of the live data and check the sensor. pressure displayed correctly, life of sensor over 6 months, status ok (not fail) sensor identity ok etc. all this with the B1344 code current. next test was obviously to swap the wheels at the front, side to side. i am sorry to report the fault stayed at the n/s/f. the das guided tests direct me to now change the N88 TPM module in the boot. however there is an antenna in each front wheel arch, as well as the central one under the floor pan.

so the question, do any of our other resident experts have any idea whether to change the N88, the antenna, check for corrosion in the plugs or do a funny dance. ie has anyone had this before? i ask just in case, this could take a while to pin down from first principles.


Always remembered RIP
I gave up on mine and had it disabled , at £100 per corner it was hopeless with so many false readings,, the guy I take it has not put the old one in the glove box or somewhere else as I have seen this before


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I would test all the wiring first Alex, be nice to send it out without the worry off seing it again for the same fault!
Alex Crow

Alex Crow

Senior Member
thanks for that guys. i can do all the tests, it is just nice to double check that there are no common faults to give these symptoms.

it was the guided test leading me to 'replace control unit' that got me, das is well written and i do wonder if i will find any other faults - wiring or otherwise. control units are always the hardest components to diagnose...