More issues Volvo S40 '05 1.8

[Scrannigan]

I'm at my effing wit's end....

Volvo S40 '05 1.8 and I'm getting anti skid service required and engine system service required with an occasional CEL and P0320 code and pending code with occasional stalling. The dash lights flash or stay on for a few seconds and the rev counter either freezes or drops to zero whilst driving, but returns to normal after a few seconds

No misfires or random symptoms from the engine itself

Only ever happens after I've been driving a little while and the engine is at temperature

Had new battery, alternator, OEM plugs, coils, camshaft and crankshaft position sensors in the last 12 months, CEM has been cleaned, all fuses have been checked, checked all visible wiring

Restarting straight away clears the ASSR and ESSR fault, but the CEL light remains only but normally restarting after five-ten minutes normally clears the CEL and stored faults