Document ID: 022899 http://gsi.xw.gm.com/si/showdoc.do?docsyskey=022899&from=sm Page of 5 2003 Chevrolet Tahoe - 4WD Avalanche, Escalade, Suburban, Tahoe, Yukon VIN C/K Service Manual Document ID: 022899 #02-05-23-004: Driver Information Center (DIC) Reduced Brake Power Message, Reduced Vacuum Boost (Inspect/Replace Intake Manifold and Recalibrate the Instrument Panel Cluster (IPC)) - (Oct, 2002) Subject: Driver's Information Center (DIC) "Reduced Brake Power" Message, Reduced Vacuum Boost (Inspect/Replace Intake Manifold and Recalibrate the Instrument Panel Cluster (IPC)) Models: 2002-2003 Cadillac Escalade 2WD 2002-2003 Chevrolet Avalanche 500 Series, Silverado, Suburban, Tahoe 2002-2003 GMC Sierra, Yukon, Yukon XL with Power Vacuum Boost Brake System (RPOs JC3 and JC4) Condition Some customers may comment on a "Reduced Brake Power" message on the DIC. Cause It is possible that a very small number of 2002 and 2003 model year vehicles may have a restriction in the vacuum booster port on the intake manifold. On the 2003 model year, only the IPC calibration is the cause of the DIC message. Correction Important: Only inspect suspect vehicles built between June 3, 2002 and August 9, 2002. Follow the service procedure below to diagnose and correct this condition.. Open the hood and install fender covers. 2. Loosen the engine sight shield bolt. The bolt should stay in the shield. 3. Remove the engine sight shield from the sight shield retainer. 200 General Motors. All rights reserved.
Document ID: 022899 http://gsi.xw.gm.com/si/showdoc.do?docsyskey=022899&from=sm Page 2 of 5 4. Inspect the left front corner of the intake manifold for a "C" with a circle around it (2). If the intake manifold DOES have a "C" (2) on it, continue with step 5. If the intake manifold DOES NOT have a "C" (2) on it, continue with step 9. 5. Disconnect the accelerator control cable clip from the engine sight shield retainer. 6. Disconnect the cruise control cable clip from the retainer if equipped. 7. Remove the engine sight shield retainer bolts and the retainer if equipped. 8. Inspect rear center of the intake manifold just below the recycle symbol for "MADE IN CANADA" (2). If the intake manifold DOES have "MADE IN CANADA" () on it, continue with step 9 If the intake manifold DOES NOT have "MADE IN CANADA" () on it, continue with step 6.
Document ID: 022899 http://gsi.xw.gm.com/si/showdoc.do?docsyskey=022899&from=sm Page 3 of 5 9. Locate the vacuum booster port connector () on the left rear of the intake manifold. 0. Gently pull out on the vacuum booster hose (2).. With two fingers, push in the vacuum booster port connector lock ring (3) while gently pulling out on the vacuum booster hose (2). Important: DO NOT force the drill bit into the vacuum booster intake port. If the vacuum booster intake port is restricted, DO NOT attempt to remove the restriction with the drill bit. If the restriction is removed with the drill bit, the material from the restriction may cause internal engine damage. If the vacuum booster port is restricted, the intake manifold must be replaced. 2. Inspect the vacuum booster intake port with a 8.7 mm (/32 in) drill bit, maximum length of 27 mm (5 in). 3. Insert the drill bit approximately 63.5 mm (2.5 in) into the vacuum booster intake port. If the vacuum booster intake port IS restricted, continue with step 4. If the vacuum booster intake port IS NOT restricted, continue with step 5. 4. Replace the intake manifold. Refer to Intake Manifold Replacement (SI Document ID # 753666). 5. Reinstall the vacuum booster hose to the vacuum booster intake port by pushing to hose nipple into the connector. 6. Install the engine sight shield retainer and the bolts. Tighten Tighten the engine sight shield retainer bolts to 5 N m (44 lb in).
Document ID: 022899 http://gsi.xw.gm.com/si/showdoc.do?docsyskey=022899&from=sm Page 4 of 5 7. Install the cruise control cable clip to the retainer. 8. Install the accelerator control cable clip to the retainer if equipped. 9. Install the engine sight shield to the retainer if equipped. Tighten Tighten the engine sight shield bolt to 0 N m (89 lb in). 20. Start the engine and fully apply the brakes four or five times in order to ensure a "good" brake pedal. Recalibrating the IPC (2003 Model Year Vehicles). Vehicles Built Prior To the following VIN Breakpoints 3G04569 3E7608 38369 3Z20443 3R07568 3J0720 2. Plug in Tech 2. 3. Set the parking brake and turn the ignition ON with the engine off. 4. Reprogram the IPC following normal SPS procedures (TIS Version 9 released August 2002 or newer). 5. After reprogramming the IPC, start the vehicle and fully apply the brakes four to five times in order to ensure a "good" brake pedal and that there are no messages on the DIC. Important: The Owner's Manual Must Be Replaced After The IPC Is Recalibrated. A new Owner's Manual can be ordered from Helm @ -800-55-423. The dealer will be billed for the new Manual and reimbursed through the warranty claims system. The Owner's Manual will be shipped to the dealer. Dealers will be required to mail the Manual to the customer. Parts Information Part Number Description Qty 73697 2558346 5757 Intake Manifold Plug, Intake Bolt, Intake Intake Gasket Set
Document ID: 022899 http://gsi.xw.gm.com/si/showdoc.do?docsyskey=022899&from=sm Page 5 of 5 73557 (02-03 Model) 7356 Throttle Body Gasket (02-03 Model) 8907230 Intake Manifold (03 Model) Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J099 Inspect Intake Manifold 0.3 hr Add To replace intake manifold.3 hrs N499 Reflash IPC (2003 Models Only) 0.4 hr 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