S10/T10 Blazer 4WD V6-4.3L VIN W (1997)
Canister Vent Valve: Testing and Inspection
***TSB Update 77-65-08, February, 1997, DTC P0442 caused by a EVAP Vent (Solenoid) Valve Leak (Check EVAP Vent Valve)******
Condition
Some vehicles may encounter, identified above, with an illuminated MIL and a stored Diagnostic Test Code P0442 (EVAP Control Small Leak
Detected).
The EVAP Vent (Solenoid) Valve (also known as EVAP Emission Canister Control Valve) may have a slight leak causing the DTC to set.
Cause
The EVAP Vent Valve plunger may be trapped (sometimes intermittently) by the plunger spring. The DTC may also be set by a small leak in the EVAP
system Diagnostic charts and procedures should be used to troubleshoot vehicles with known good EVAP Vent Valves.
Correction
An improved EVAP Vent Valve (P/N 12559015) has been put into production and released for service. Parts are currently available from GMSPO.
