Steering Wheel Pulse/Nibble - RAS/EVO Module (91-16-5)

SUSPENSION - REAR - RAS/EVO (REAR AIR SUSPENSION/ELECTRONIC VARIABLE ORIFICE) MODULE OVERLY SENSITIVE

Model FORD: 1992 CROWN VICTORIA

LINCOLN-MERCURY: 1991-92 TOWN CAR

1992 GRAND MARQUIS Group Steering & Suspension Bulletin No. 92-8-6 Date April 8, 1992 Symptom Steering Pulsing/Nibbling; Overly Sensitive Suspension

ISSUE:

Some power steering systems may be overly sensitive to

small variations in the level of assist made by the RAS/EVO

(Rear Air Suspension/Electronic Variable Orifice) module.

Customers may feel a light pulsation or nibble through the

steering wheel during freeway exit ramp turns. The steering

nibble may be experienced at vehicle speeds of about 44 mph

(71 km/h). Steering function is not affected.

These conditions occur because the RAS/EVO module is fine

tuning the level of power steering assist.

ACTION:

Test drive the vehicle and, if necessary, replace the

RAS/EVO module. Refer to the following procedure for

service details.

SERVICE PROCEDURE:

1. Turn OFF the air suspension/variable power steering switch located on the right rear quarter panel in the trunk compart- ment.
2. Test drive the vehicle to confirm that the pulsation/nibble is gone.
3. If the condition is gone, replace the RAS/EVO module. * In the Town Car, the module is located on the right hand side of the trunk compartment. * In the Crown Victoria/Grand Marquis, the module is located on the left side seat back/package tray accessed through the trunk.
4. Tighten the module mounting screws to 45-53 lb-in (5-6 N-m).
5. Turn on the air suspension/variable power steering switch.
6. If the condition does not go away, refer to the appropriate Steering Gear and Power Steering Pump Diagnostic procedure.

Part Number	Part Name	Class
F2VY-5A919-A	RAS/EVO Module	B