AIR Pump - Hesitation on Acceleration/DTC's Set

File In Section: 06 Engine/Propulsion System

Bulletin No.: 01-06-04-011

Date: March, 2001

TECHNICAL

Subject:
Water in AIR Pump and/or DTC P0410, P0412, P0415, P0416, P0100, P0101,
P0102 or DTC 48 (AIR System Disable Procedure)

Models:
1995-1996 Buick Roadmaster
1995-1996 Cadillac Fleetwood
1995-1996 Chevrolet Caprice, Impala SS
with 4.3L or 5.7L Engine (VINs W, P - RP0s L99, LT1)

Condition

^ Some customers may comment of a hesitation during heavy/full throttle acceleration.

^ A 1996 vehicle may also set any of the following DTCs:

- P0410
- P0412
- P1415
- P1416
- P0100
- P0101
- P0102

^ A 1995 vehicle may set a DTC 48.

^ There will also be evidence of water in the AIR pump.

Cause

Under high engine speed and load conditions, hot exhaust gasses may leak past the air check valves. As the exhaust gasses in the air tube cool, water vapors collect into the AIR pump. As the vehicle is driven, condensation from the AIR pump may come into contact with the Mass Airflow Sensor through the AIR inlet hose. This condition may cause a hesitation on acceleration and may also set the DTCs.

Correction

To correct this condition, a Secondary AIR Injection Pump disable procedure has been developed. (It has been determined that the Secondary AIR Injection system is not required to meet emission requirements for these vehicles only.)





1. Locate the relay center (1) and air cleaner box (2).





2. Remove the AIR hose and clamp (1) from the air cleaner box.

3. Insert the plug (2) into the air cleaner box AIR hose inlet (3).

4. Install the AIR hose and clamp (1) to the air cleaner box.





5. Remove the cover (1) from the relay center (3).

6. Remove AIR pump relay (2) from the relay center (3).





7. Install the relay cover (1)

8. Install new emission label to radiator support (3).

9. Update vehicle calibration. (1995 4.3 L L99 Caprice, and 1996 vehicles).





Parts Information

Parts are currently available from GMSPO.

Calibration Information

The Calibrations are electronic calibrations and are NOT available from GMSPO. Calibrations will be available from Techline starting February 2001, on the TIS 2000 version TIS 2.0/2001 data update or later.

Warranty Information





For vehicles repaired under warranty, use table shown.





1995 4.3 L (RP0 L99) Caprice and 1996 vehicles should also use additional table shown add time for reprogramming.





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