Engine Controls - Normal Procedures Do Not Fix Code 53
Number: 86-180Section: 6E
Date: Oct. 1986
Subject: CODE 53 - EGR CONTROL ERROR
MODEL AND YEAR: 1986 CAPRICE WITH 5.0L LG-4 ENGINES (ENGINE CODE H)
TO: ALL CHEVROLET DEALERS
In most cases, normal diagnostic and repair will correct customer complaints of "Service Engine Soon Light" Code 53 (EGR Control Error). If the diagnostics shown in your 1986 Shop Manual (Section 6E1) shows the problem to be no trouble found, it will be necessary to change the PROM in the ECM. Below is a listing of new PROM numbers released to correct this condition.
On Federal Emission (NA-5) Caprice Models
1. Coupes and Sedans Use PROM 1228284
2. Wagons with GU2 (2.73) Axle Use PROM 1228285
3. Wagons with GU4 (3.08) Axle Use PROM 1228286
On California Emission Caprice Models
1. Coupes and Sedans Use PROM 1228287
2. Wagons with GU2 (2.73) Axle Use PROM 1228288
3. Wagons with GU4 (3.08) Axle Use PROM 1228289
Use applicable Labor Time and Operations Numbers.