All sensors are saying ready for E test but the engine light is on because of clutch fan. When the engine light is turned off with scanner the o2 sensor ,cat converter and evaporater go to not ready for e test. When engine light is turned off as soon as u shut the truck off and start it again the light comes back on again. The scanner is reading 503 for fan rpm but the scanner wants to see 302 rpm when idling. My old clutch fan was seized and tore the wire harness got another clutch from the wreckers
Engine light is on it is the clutch fan that is causing it on 2003 GMC Envoy
by Hto2go in Niagara Falls, NY on April 08, 2013
ANSWER by arturo08 , April 10, 2013
poss. issue with wreckers fan. never a sure thing with second hand parts.
ANSWER by vonte , June 04, 2013
My clutch fan will stop my truck from cranking