Radio code query
2005 156 1.9 Jtdm, duff alternator flattened battery, radio code not accepted after CODE and four dashes, code entered within 20secs, get WAIT. It times out, then try again, but code still not accepted. I believe I've used the code successfully before, but can't be sure. Before removing radio to establish S/No, is there any other way to sort this out, please?
Various posts have suggested leaving the radio on for 1 hour, then entering the code before switching ignition off - would this apply even after the normal procedure above has been tried? If so, why?
Something's also been mentioned about resetting ECU - would this apply in this case?