G 1500 1/2 Ton Van V8-305 5.0L VIN H 4-bbl (1984)
Diode: Customer Interest
ECM - False Setting of Trouble Code 42
FALSE SETTING OF TROUBLE CODE 42 CALIFORNIA EMISSIONS ONLY
Model and Year:
1984 "S/T" TRUCK 2.8L RPO LR2 WITH YF5 CALIFORNIA EMISSIONS AND 1984 "G" VAN 4.1L, 5.0L, 5.7L RPO LE3,
LF3, LS9 WITH YF5 CALIFORNIA EMISSIONS, WITHOUT GAUGE PACKAGE
ALL CHEVROLET DEALERS
A false Trouble Code 42, Electronic Spark Timing (EST) may be stored in the Electronic Control Module (ECM). This condition does not cause a
typical EST type condition such as "no start", "starts/will not run" or a change in RPM.
A false Trouble Code 42 can be detected in one or two ways, either the check engine light is on continuously or there is no check engine light on,
however, a Code 42 is stored in the ECM.