Question

2003 GMC Envoy 4.2 codes U 1000,1238,1255

Answer 1

Whenever U1000 appear it also codes U1255 they go together, what this is a history code condition that can have been set do to recent changes IE. LEts say you took out the instument panel and started the vehicle you would would code a U1000 and a U1255 until the instument panel was restored. A low battery codnition can set this code, U code are usually temporary codnition and usually correct itself.