PIP5280

Bulletin No.: PIP5280
Date: Apr-2015
Subject:
Fuel Pressure Regulator Buzz And/or Hum Noise
Models:
1999-2003 Chevrolet Avalanche, Silverado, Suburban, Tahoe, Express
1999-2003 GMC Sierra, Yukon, Savana
Built with engines - 4.8 LR4, 5.3 LM7, 5.3 L59, 6.0 LQ4, or 6.0 LQ9
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
Some vehicles may exhibit a hum / buzz noise at idle after fuel pressure regulator replacement.
If the vacuum line is removed from the fuel pressure regulator, the noise may change or stop completely.
Recommendation/Instructions
Check the power and ground feeds to the fuel pump for voltage drops with key on engine off, all the way from the battery posts.
We recommend a load of at least 3 amps at the fuel pump electrical connector and wiggling all the connectors.
Also check all pin fit and terminal drag.
Engineering introduced a redesigned fuel pump connector for service in December 2004 (see service bulletin 04-06-04-088C).
The new fuel pump connector requires crimping to make the electrical connection, and we have seen that Tech's are sometimes introducing excessive
resistance at the crimps due to incorrect or worn crimping tools AND/OR not shrinking the splice sleeve completely to seal the joint.
Other possible voltage drop points include the UBEC, fuel pump relay, and ground at the frame and the battery cable grounds.
If excessive resistance is found at the crimps, replace the crimp n seal splice sleeves for the affected circuits.
The J-38125-H terminal repair kit contains the splice sleeves to be used in the repair, part number 12089190 (blue) splice sleeves are found in tray 1 and are
used for the fuel pump circuits. Part number 12089189 (salmon) splice sleeves are also found in tray 1 and are used for the fuel level sender circuits.
If the circuits show not to have high resistance use the following regulator part number.
19236428 FUEL INJECTION PRESSURE REGULATOR (ACDelco #217-3299)
Warranty Information
For wiring repairs covered under warranty, please refer to latest version of bulletin 10-00-89-005 for warranty information on wire/connector repairs.
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
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