car died---hard to re-start--code P0506

180,000 mi. 1997
Has original battery and alternator (amazing) and when it died it was in gear when i just pulled up to a light. Lights were doing strange things so i first thought alternator. Tested it and it doesn't seem to be getting much of a charge to the battery, if any.

I was all ready to re-place both and then i noticed the check engine light on. Code reader said P0506 (idle control system-low idle).

Could a bad alternator-battery produce the low idle code? Or do I have a different problem than I thought? Thanks.

180,000 mi. 1997
Has original battery and alternator (amazing) and when it died it was in gear when i just pulled up to a light. Lights were doing strange things so i first thought alternator. Tested it and it doesn't seem to be getting much of a charge to the battery, if any.

I was all ready to re-place both and then i noticed the check engine light on. Code reader said P0506 (idle control system-low idle).

Could a bad alternator-battery produce the low idle code? Or do I have a different problem than I thought? Thanks.

code 0506 means idle control system RPM lower than expected

check in battery and alternator separately

it could be because if is no charge or low charge sparks is getting lower
power resulting in bad explosion on pistons

Replaced alternator, plugs and wires, PCV valve. Battery OK.

Gave up and took it in.

Idle air control valve was bad.

Ironically, i almost replaced it myself. DAMN IT!