Fuel systemModel years 1999–2003Manufacturer
Fuel pressure regulator buzz / hum after replacement (check fuel pump feed voltage drop and connector crimps)
1999-2003 GMC Sierra, Yukon, Savana (and Avalanche, Silverado, Suburban, Tahoe, Express) built with 4.8 LR4, 5.3 LM7, 5.3 L59, 6.0 LQ4 or 6.0 LQ9
FaultCrate・Fuel pressure regulator buzz / hum after replacement (check fuel pump feed voltage drop and connector crimps)
Some vehicles may have a hum / buzz noise at idle after fuel pressure regulator replacement.
Engineering introduced a redesigned fuel pump connector for service in December 2004 (bulletin 04-06-04-088C).
Technicians sometimes introduce excessive resistance at the crimps of the new connector through incorrect or worn crimping tools or by not fully shrinking the splice sleeve.
What to do
- If the vacuum line is removed from the regulator, the noise may change or stop completely.
- Check the power and ground feeds to the fuel pump for voltage drops, key on engine off, all the way from the battery posts.
- Other possible voltage drop points include the UBEC, fuel pump relay, the frame ground and the battery cable grounds.
- If excessive resistance is found at the crimps, replace the crimp-and-seal splice sleeves for the affected circuits.
In the records
- Fuel Pressure Regulator: replaced 1
- Fuel Pump Connector: replaced 1
Applies to
- The bulletin covers 1999-2003 GMC Sierra, Yukon and Savana.
- It applies to engines 4.8 LR4, 5.3 LM7, 5.3 L59, 6.0 LQ4 or 6.0 LQ9.
See the evidence (1 documents, 9 passages)
| Document | Publisher | Date |
|---|---|---|
| [1]PIP5280: Fuel Pressure Regulator Buzz And/or Hum Noise ↗ | ManufacturerGeneral Motors (published by NHTSA) | 2015-04-07 |
Applies toThe bulletin covers 1999-2003 GMC Sierra, Yukon and Savana.
1999-2003 GMC Sierra, Yukon, Savana— [1] Models
Applies toIt applies to engines 4.8 LR4, 5.3 LM7, 5.3 L59, 6.0 LQ4 or 6.0 LQ9.
Built with engines - 4.8 LR4, 5.3 LM7, 5.3 L59, 6.0 LQ4, or 6.0 LQ9— [1] Models
First signsSome vehicles may have a hum / buzz noise at idle after fuel pressure regulator replacement.
Some vehicles may exhibit a hum / buzz noise at idle after fuel pressure regulator replacement.— [1] Condition
How to confirmIf the vacuum line is removed from the regulator, the noise may change or stop completely.
If the vacuum line is removed from the fuel pressure regulator, the noise may change or stop completely.— [1] Condition
How to confirmCheck the power and ground feeds to the fuel pump for voltage drops, key on engine off, all the way from the battery posts.
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.— [1] Recommendation
Why it happensEngineering introduced a redesigned fuel pump connector for service in December 2004 (bulletin 04-06-04-088C).
Engineering introduced a redesigned fuel pump connector for service in December 2004 (see service bulletin 04-06-04-088C).— [1] Recommendation
Why it happensTechnicians sometimes introduce excessive resistance at the crimps of the new connector through incorrect or worn crimping tools or by not fully shrinking the splice sleeve.
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.— [1] Recommendation
How to confirmOther possible voltage drop points include the UBEC, fuel pump relay, the frame ground and the battery cable grounds.
Other possible voltage drop points include the UBEC, fuel pump relay, and ground at the frame and the battery cable grounds.— [1] Recommendation
RepairIf excessive resistance is found at the crimps, replace the crimp-and-seal splice sleeves for the affected circuits.
If excessive resistance is found at the crimps, replace the crimp n seal splice sleeves for the affected circuits.— [1] Recommendation
Put together by FaultCrate from public records and technical documents. The cause and the repair are for the workshop to decide with the vehicle in front of it. Counts are records, not failure rates.
List the records (1 that can be opened)
Records whose recall number, document number or text matches. Each line says why it matched.
- Buzz Noise at Idle After Fuel Pressure Regulator ReplacementManufacturer communication 2017-08-15・document number matches