Diagnose and fix P0171 Chevrolet Colorado
Owners of Chevrolet Colorados are reporting trouble code P0171 Fuel Trim System Lean. GM has issued a service bulletin #PIP4409F: SES LIGHT WITH DTCS P0106, P0107, P0171, P0300, P0502, P1107 P2431 to address the issue on the vehicles listed below.
GM service bulletin #PIP4409F findings
GM reports that owners may experience an intermittent rough running concern and a check engine light with misfires on all cylinders along with one or more of the following trouble codes: P0106, P0107, P0171, P0300, P0502, P1107, P2431.
GM advises techs to inspect the MAP sensor circuits, looking for a break in one of the wires to the MAP sensor within inches of the connector
If you find a break, repair and waterproof the repair.
Vehicles affected by GM service bulletin #PIP4409F
2004-2012 Chevrolet Colorado 2.8L (LK5), 2.9L (LLV) or 3.7L (LLR)
2004-20122 GMC Canyon.8L (LK5), 2.9L (LLV) or 3.7L (LLR)
2006-2010 Hummer H3 2.8L (LK5), 2.9L (LLV) or 3.7L (LLR)
Other causes of P0171
Cracked PCV hose can cause an air leak
In addition to the broken MAP wire, you may also find a damaged PCV hose that’s allowing too much unmetered air into the engine. Check the PCV hose for damage, cracks, opens.
Cracked air intake duct can cause P0171
Check the air intake duct that runs from the filter box to the throttle body for cracks, tears. If you find any, replace the duct.
©, 2021 Rick MuscoplatPosted on by Rick Muscoplat