GM Service Manual Online
For 1990-2009 cars only

Compressed Natural Gas (CNG) Fuel Pressure Relief Caution for Chevrolet Colorado Pickup - 2WD 2008

Caution: The Compressed Natural Gas (CNG) system operates at pressures up to 24820 kpa (3600 psi). Relieve the CNG fuel system pressure before servicing CNG fuel system components in order to reduce the risk of fire and personal injury.