Code 67, A/C Pressure Sensor: Notes

PCM determines when A/C clutch is engaged by monitoring A/C status line. Code will set if PCM does not detect an A/C refrigerant pressure change of more than 9 psi when A/C clutch has cycled.

1. Checks for an A/C pressure increase of at least 9 psi when A/C clutch is engaged.
2. If relay power feed is intermittent, A/C clutch status terminal may not detect voltage when A/C is commanded on.
3. If A/C clutch status line becomes intermittently open or shorted while compressor is on, PCM will wrongly detect A/C clutch going on and off. When this occurs and clutch remains engaged, PCM will not detect pressure change and a Code 67 will be set.
4. 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 PCM 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.
5. The remaining tests check the A/C refrigerant pressure sensor circuit for proper operation.