Arizona BS Thread
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Joined: 02-16-10
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From: Queen Creek,AZ
Senior Member
Joined: 10-08-06
Posts: 3,043
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From: Scottsdale, AZ
For EJ:
Condition/Concern:
A technician may find DTC P2261: Turbocharger Bypass Valve Stuck Closed set with no problem found. It may be intermittent in nature or they may find the dtc will set after a hard acceleration, usually in third gear. DTC P2261 is a type B dtc and will not set on the first drive cycle the dtc sets, therefore multiple test drives should be performed to confirm repair.
Recommendation/Instructions:
SI diagnostics for this DTC states that the ECM compares the measured MAF reading to the modeled MAF and has detected a series of pulsations in the induction system that exceed a calibrated threshold. A snapshot of "Induction Data" will show the fault, however the tech may need to compare the snapshot data to another vehicle if they are unfamiliar with the readings. They should note a fluctuation and or a difference in the desired versus requested boost level. When diagnosing this dtc pay close attention to Circuit/System testing step #1. This step has you inspecting for any vacuum leaks, damage, restrictions, improper routing or connecting of the vacuum hoses on the charge air bypass valve solenoid, the charge air bypass valve, and the charge air bypass valve vacuum tank.
We have found leaking vacuum tanks causing this dtc. When testing the vacuum tank, care must be used or the results may not be valid. The vacuum tank has an integral check valve not noted in SI. To check the Vacuum Tank operation, disconnect the hose that runs from the tank to the Bypass Valve Solenoid at the solenoid and apply vacuum to the tank. The tank should be able to maintain vacuum with no decay. Note: If you remove the vacuum hose from the intake manifold and plug it and the decay stops the check valve is leaking, if the decay continues the tank itself is leaking.
Note: Front wheel drive platforms using the 2.0 Liter RPO (LNF) incorporate a charge air bypass valve supplemental vacuum tank. The purpose of the tank is to provide an instant source of vacuum to the bypass valve via the bypass solenoid (when it is commanded open by the ECM). This results in less pressure buildup under closed throttle conditions, thereby reducing compressor noise, surge and spool time.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
Š 2009 General Motors Corporation. All rights reserved.
Condition/Concern:
A technician may find DTC P2261: Turbocharger Bypass Valve Stuck Closed set with no problem found. It may be intermittent in nature or they may find the dtc will set after a hard acceleration, usually in third gear. DTC P2261 is a type B dtc and will not set on the first drive cycle the dtc sets, therefore multiple test drives should be performed to confirm repair.
Recommendation/Instructions:
SI diagnostics for this DTC states that the ECM compares the measured MAF reading to the modeled MAF and has detected a series of pulsations in the induction system that exceed a calibrated threshold. A snapshot of "Induction Data" will show the fault, however the tech may need to compare the snapshot data to another vehicle if they are unfamiliar with the readings. They should note a fluctuation and or a difference in the desired versus requested boost level. When diagnosing this dtc pay close attention to Circuit/System testing step #1. This step has you inspecting for any vacuum leaks, damage, restrictions, improper routing or connecting of the vacuum hoses on the charge air bypass valve solenoid, the charge air bypass valve, and the charge air bypass valve vacuum tank.
We have found leaking vacuum tanks causing this dtc. When testing the vacuum tank, care must be used or the results may not be valid. The vacuum tank has an integral check valve not noted in SI. To check the Vacuum Tank operation, disconnect the hose that runs from the tank to the Bypass Valve Solenoid at the solenoid and apply vacuum to the tank. The tank should be able to maintain vacuum with no decay. Note: If you remove the vacuum hose from the intake manifold and plug it and the decay stops the check valve is leaking, if the decay continues the tank itself is leaking.
Note: Front wheel drive platforms using the 2.0 Liter RPO (LNF) incorporate a charge air bypass valve supplemental vacuum tank. The purpose of the tank is to provide an instant source of vacuum to the bypass valve via the bypass solenoid (when it is commanded open by the ECM). This results in less pressure buildup under closed throttle conditions, thereby reducing compressor noise, surge and spool time.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
Š 2009 General Motors Corporation. All rights reserved.
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Joined: 02-12-09
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From: Phoenix
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Joined: 10-08-06
Posts: 3,043
Likes: 0
From: Scottsdale, AZ
Drive fine the lil I drove today. Its really easy if you need any help let me know. I need to pull my plugs and tighten the gap a lil more
Senior Member
Joined: 10-08-06
Posts: 3,043
Likes: 0
From: Scottsdale, AZ
Senior Member
Joined: 02-12-09
Posts: 2,129
Likes: 0
From: Phoenix
Omg nick we have the same **** going on i have an exhaust leak too i cant find though lol how does yours sound? Mine sounds like its from the downpipe off the turbo mani but thats not it i tightend every bolt down 2 or 3 times now
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Joined: 07-29-05
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From: AZ
okay so I lied, finally popped a code for cyl 4 misfire. i made sure all of my injectors were seated properly and swapped out my plugs and all seems to be well
yeah i know man I was thinking the same thing today. i wonder if id be able to save some dough by just swapping to a gen II LE5 block?
i'm kinda scared to build my own motor honestly though
i'm kinda scared to build my own motor honestly though
Senior Member
Joined: 10-08-06
Posts: 3,043
Likes: 0
From: Scottsdale, AZ
Its a ticking noise on cold starts and when I put load on the car but it goes away after it gets warmed up
Senior Member
Joined: 10-08-06
Posts: 3,043
Likes: 0
From: Scottsdale, AZ
This sound is not normal. Everything is louder in my car since I built the motor and installed the spec 3+ and flywheel
Senior Member
Joined: 02-16-10
Posts: 8,383
Likes: 1
From: Queen Creek,AZ
okay so I lied, finally popped a code for cyl 4 misfire. i made sure all of my injectors were seated properly and swapped out my plugs and all seems to be well
yeah i know man I was thinking the same thing today. i wonder if id be able to save some dough by just swapping to a gen II LE5 block?
i'm kinda scared to build my own motor honestly though
yeah i know man I was thinking the same thing today. i wonder if id be able to save some dough by just swapping to a gen II LE5 block?
i'm kinda scared to build my own motor honestly though