Eric - Plug Guy

Last week I cranked up the '04 C4S Cab and the radio came on properly but without sound. Well, except for a high pitched whistle. Display was fine. Just no true audio. All memory settings and stations were fine.

Turned off the car, restarted, radio was fine again.

Happened again last night. Turning off just the radio won't solve it. But turning off the car, then back on a minute later, seemed to.

I'm sure it's a head unit replacement issue, just wondered if anyone has had this happen.

Thanks.

ltc

Eric,
You are correct in that just turning the key on/off won't 'reset' it. You have to wait a few minutes for the MOST ring to shut down (the lighted ring around your headunit's volume **** goes off....or just wait about 3-4 minutes).

It may not be a headunit issue, it could also be an initialization error in the MOST DSP amplifier (although when this happens, you normally get no audio, not exactly what you described).

It has been corrected in several ways:
1. The MOST DSP amplifier (mounted under the front bonnet) is simply replaced with a newer/current production model (has latest S/W).
2. The MOST DSP amplifier S/W is updated by inserting a CDROM into the headunit and updating the Flash memory over the MOST ring (all MOST components are updated in vehicle this way).

If that's not it, then the next step would be a headunit update/replacement.

Your dealer should be aware of all of these procedures and able to accomodate you quite easily.

If they give you a hard time, tell them to either fix it or the designer of the damned thing will "pay them a little visit"

Eric - Plug Guy

Hehehe...thanks L. Knew I could count on you bud!

ltc

Next time just send me a PM....I would have felt worse if I had never seen the thread and left you hanging....
Like I said, this should be an easy warranty repair.