PROM - More Than Normal Black Smoke At Idle

89Chevy29

GMC NUMBER: 89-T-71


GROUP: 6E - Engine Emission

DATE: June, 1989


CORPORATE
NUMBER: 936503R
SUBJECT: MORE THAN NORMAL BLACK SMOKE AT IDLE

MODELS: 1988 AND EARLY 1989 C/K/R/V/G TRUCKS W/6.2L (VIN C) DIESEL
Comments have, been received of more than normal black smoke at idle on the above mentioned vehicles. To correct this black smoke condition, the Engine Control Module (ECM) calibration has been modified to enhance the regulation of the Exhaust Gas Recirculation circuit at idle. Listed below are the replacement PROM's required to service the 1988-89 model vehicles.

Replacement
Broadcast Scanner PROM
Code I.D. P/N Model
1988
APYC Visual 16133376 R/V C/K/G ALL MODELS
Inspection
1989
APXY 3381 16133879 R/V 1 AND MD8
G2 AND MY6
APXZ 3391 16141815 C/K 1, 2 AND M20
C1 AND MD8
APYA 3401 16133888 C2 AND MD8
K1, 2 AND MD8 G2 AND MD8
Parts are currently available from GMSPO. 1988 vehicles require visual inspection of the PROM Broadcast label for ECM identification (I.D.). Tech I Scan tool may be used to identify ECM calibration on 1989 vehicles. Current service procedure for PROM replacement should be used.

Labor Operation Number: T0500
Labor Time: .6 Hr