Code 67 - A/C Pressure Sensor (3.4L "F" Body): Notes
WARNING: This page is about a different car, the 1993 Pontiac Grand Prix, 1993 Pontiac Firebird, 1993 Oldsmobile Cutlass Supreme, 1993 Chevrolet Lumina, and 1993 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
ECM determines when A/C clutch is engaged by monitoring A/C status line. If A/C pressure does not increase by at least 9 psi when A/C clutch is turned on, Code 67 will set.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- Code 67 will set if ECM does not detect a A/C pressure increase of at least 9 psi when A/C clutch is engaged.
- If relay power feed is intermittent, A/C clutch status terminal may not detect voltage when A/C is commanded on.
- If A/C clutch status line becomes intermittently open or shorted while compressor is on, ECM will wrongly detect A/C clutch going on and off. When this occurs and clutch remains engaged, ECM will not detect pressure change and a Code 67 will be set.
- If A/C compressor clutch is disconnected or if A/C status circuit is open between splice and clutch, compressor clutch will not engage, but ECM will detect voltage on A/C status line, which will indicate clutch is on. If A/C switch is cycled on and off at this point, no pressure change will be detected and a Code 67 will set.
- The remaining tests check the A/C refrigerant pressure sensor circuit for proper operation.