GMC Yukon 2000–2006

From the manufacturer’s document

• Applies to：Applies to Buick, Cadillac, Chevrolet and GMC passenger cars and trucks, model years 2000 to 2022, gasoline engines only.
• Condition：Customers may comment that the MIL is illuminated.
• Condition：Initial diagnosis may show fuel trim and O2 sensor related codes including P0101, P0137, P0138, P0140, P0141, P0157, P0158, P0160 and P0161.
• Condition：The listed codes also include P0171, P0174, P0420, P0430, P1174 and P1175.
• Confirm：If normal SI diagnostics do not lead to a resolution and an intake vacuum leak or exhaust leak is suspected, use the GE-52250 Variable Pressure Leak Detector (preferred), the J-41416 ultrasonic leak tester, or possibly soapy water with low pressure air into the tailpipe to find the leak.
• Caution：All of these tests are much more effective if the throttle body is covered or sealed.
• Confirm：For an intake leak, introduce the smoke into the brake booster hose or the oil dipstick tube; soapy water can be sprayed near the gasket, seams and all vacuum nipples.
• Confirm：For an exhaust leak, put the hose with smoke or air into the tailpipe sealed with shop towels, then spray soapy water around seals, seams and bosses.
• Cause：These methods find small leaks around the O2 sensor embossments and slight cracks in an intake plenum or gasket.
• Parts：No parts are required for this repair.

From the manufacturer’s document

• Applies to：The model table lists all models, 2000 - 2019.
• Condition：On vehicles with turbocharged gasoline engines, poor engine performance or an engine light in cold ambient temperatures may set one or more of DTCs P0171, P0172, P0299 and P2227.

From the manufacturer’s document

• Applies to：Applies to all 2000 - 2019 models with gasoline engines.
• Condition：The SES light is on, and initial diagnosis may show fuel trim and/or O2 sensor related codes such as P0171, P0174, P0420 and P0430.
• Confirm：If normal SI diagnostics do not resolve it and an intake vacuum leak or exhaust leak is suspected, the J41413-200 Evaporative System Tester smoke machine, the J-41416 ultrasonic leak tester, or soapy water with low pressure air into the tailpipe may help find the leak.
• Caution：All of these tests are much more effective if the throttle body is covered/sealed.
• Confirm：For an intake leak, the smoke can be introduced into the brake booster hose or the oil dipstick tube.
• Confirm：Soapy water can be sprayed near the gasket and seams and on all vacuum nipples.
• Confirm：For an exhaust leak, a hose into the tailpipe carrying smoke or air, sealed with shop towels, is effective.
• Confirm：Then spray soapy water around the seals, seams and bosses.
• Confirm：These methods are very good for finding small leaks around the O2 sensor bosses and slight cracks in an intake plenum or gasket.

From the manufacturer’s document

• Applies to：Applies to all brands and models with gasoline engines, model years 2000 - 2022.
• Applies to：The involved region is North America.
• Condition：In rare instances customers may complain of a fuel smell, longer starts, hesitation and, in extreme cases, engine stalls.
• Condition：Any combination of DTCs P0300, P0171, P0174 and P228C may be set.
• Cause：Using winter fuel in summer weather may cause drivability concerns.
• Confirm：The concern should not be a single event but multiple occurrences associated with hot days.
• Caution：No repair is required; the vehicles are not damaged and will recover.
• Caution：There is no other remedy until summer fuel and/or cooler weather is available.

From the manufacturer’s document

• Applies to：The list of compatible flexible-fuel vehicles includes 2002–2005 fullsize pickups and utilities with 5.3L, RPO L59.
• Applies to：The list of compatible flexible-fuel vehicles includes 2006 Sierra, Yukon and Yukon XL with 5.3L, RPO L59.
• Caution：All Model Year 2011 and older non-FFV gasoline vehicles are designed to run on fuel containing no more than 10% ethanol.
• Caution：Diesel engines are not E85 compatible.
• Condition：Using this fuel in a non-compatible vehicle may cause lean driveability concerns such as hesitation, sag and/or possible stalling.
• Condition：Fuel trim DTC P0171 and/or P0174 may set.
• Condition：Misfire DTC P0300 may set.
• Condition：A Traction Control, Stability System or ABS lamp may illuminate, or a message may display in the DIC (if equipped).
• Condition：Harsh and/or firm transmission shifts may occur because the transmission defaults to maximum line pressure.
• Confirm：Alcohol content is checked using Special Tool J-44175-A Fuel Composition Tester or CH-44175-A Fuel Composition Tester.
• Repair：If the ethanol content exceeds the Owner Manual maximum of 10% or 15%, drain the fuel and refill the vehicle with gasoline, preferably a Top Tier brand.
• Confirm：General Motors started putting yellow gas caps on E85 Flex Fuel Vehicles (FFVs) as of Model Year 2006.