Cruise Control - Tap Up or Tap Down Response
89Chevy16Number: 88-394-9B
Section: 9B
Date: MARCH, 1989
Subject: CRUISE CONTROL - "TAP UP OR TAP DOWN RESPONSE"
Model and Year: 1988 R1, R2, V1, V2 TRUCKS WITH 5.7L OR 7.4L
TO: ALL CHEVROLET DEALERS
Some 1988 R/V Suburban/Blazers within the VIN breakpoints listed below, equipped with 5.7L or 7.4L gasoline engines and cruise control may exhibit a condition involving cruise control response. Acceleration several mph more than expected may occur when the driver uses the Tap-up or Tap-down cruise modes. This may be caused by voltage transients induced during engine start.
A cruise control module which is less susceptible to negative voltage transients has been released.
Vehicles Involved
1988 Suburban/Blazer equipped with 5.7L or 7.4L engines and cruise control (K34) built within the following VIN breakpoints:
From Through
JF126643 JF182301
Figure 1:
Service Procedure
Cruise control module replace. Refer to Figure No. 1.
1. Disconnect cruise harness (121).
2. Disconnect module assembly (116) by prying back the retaining clip on the bracket and sliding the module out.
3. Install new module P/N 25110868.
4. Connect cruise harness.
PARTS INFORMATION
PART PART NUMBER QUANTITY
Cruise control module 25110868 1
Parts are currently available from GMSPO.
The labor operation to replace the cruise control module is:
Labor Op: R1220
Labor Time: .3 Hr