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For 1990-2009 cars only

SMU - Revised DTC P1221

Subject:Revised DTC P1221

Models:2001-2002 Chevrolet Corvette
2001 Chevrolet and GMC C/K Pickup and Utility Models (Silverado, Sierra, Sierra C3, Suburban, Tahoe, Yukon, Yukon XL)
2001 Chevrolet and GMC G-Van Models (Express, Savana)
2001-2002 Chevrolet and GMC 3500 HD Models
2001-2002 Chevrolet and GMC C-Series Medium Duty Conventional Cab Models
2001-2002 Chevrolet and GMC B7 Medium Duty School Bus Models
With 4.8L, 5.3L, 5.7L, 6.0L or 8.1L Engine (VINs V, T, G, S, U, G -- RPOs LR4, LM7, LS1, LS6, LQ4, L18)



This bulletin is being issued to revise step 2 of DTC P1221 in the Engine Controls sub-section of the Service Manual. Please replace the current information in the Service Manual with the following information.

The following information has been updated within SI2000. If you are using a paper version of this Service Manual, please make a reference to this bulletin on the affected page.

The text "DTC P1515" has been deleted in step 2. Step 2 of this diagnostic table should read as follows:

Step

Action

Yes

No

2

Is DTC P1518 also set?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3