INTERMITTENT OR HARD CODE E49 REPLACE AIR MANAGEMENT VALVE

SUBJECT: INTERMITTENT OR HARD CODE E49 (REPLACE AIR MANAGEMENT VALVE)

VEHICLES AFFECTED: 1990 C, E, K

* This bulletin is being revised to include additional diagnosis.

Some 1990 DeVilles, Fleetwoods, Eldorados, and Sevilles may experience a code E49. The code may be caused by vacuum supply to the air management valve, air management valve circuits leaking, fuel injectors, or an internal condition in the air management valve.

To repair this condition, use the following procedure:

1. Visually inspect for vacuum hoses pinched, kinked, or disconnected.

2. Follow trouble tree C-6 on page 6E-C6-11 of the Service Information Manual to check solenoid circuits.

3. Perform "Injector System Diagnosis" chart A-5 from Section 6E-A of the Service Information Manual to verify injectors are not leaking.

4. Check air pump output by placing hand over output hose while revving the engine to 1500 rpm in park. the force of the air should be sufficient to blow one's finger off the line. If the output of the pump is good, go to step 8. If is is weak, perform steps 5 through 7 below.

5. Check the air pump input for any water or oil (contaminants that enter the pump will damage the carbon seals and vanes causing reduced output). Inspect and clear outlet tubes, check valve, and air management valve of any debris.

6. Check the PCV valve operation per 6E-C13 in the Service Information Manual and verify it is not allowing oil into the air cleaner.

7. Replace the low output air pump with P/N 26006809.

8. Check air management check valve operation per page 6E-C6-2 in the Service Information Manual.

9. If the system operates to specification in the above checks, replace the air management valve (P/N 17090215).

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those 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 a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.