G 2500 3/4 Ton Van V6-262 4.3L VIN Z (1992)
Follow standard detonation diagnostic procedures in the appropriate service manual. If the cause of the detonation cannot be determined and eliminated
after standard diagnostic procedures, the condition may be corrected by the installation of the correct field fix calibration PROM from the table.
NOTE:
The manual transmission calibrations contain the neutral gear rattle update (increased idle speed). If a vehicle is experiencing neutral gear rattle,
hardware changes and the new calibration are required. For a description of neutral gear rattle and the required hardware changes, see Corporate
Bulletin 267201.
NOTE:
The S/T series automatic transmission calibrations contain the torque converter clutch (TCC) lock-up update. For a description of the TCC update,
see Corporate Bulletin 137107.
WARNING:
Use of a detonation field fix calibration PROM in a nondetonating engine may result in degraded driveability. General Motors strongly recommends
the concern be properly identified as sustained detonation occurring after the engine is fully warmed to normal operating temperature.
