B1348

CIRCUIT DESCRIPTION
In the process of controlling the compressor clutch, the Air Conditioning Programmer (ACM) monitors certain system inputs for an indication of low refrigerant charge. The ACM monitors the normally closed low refrigerant pressure switch at pin "D14." The status of the low pressure switch is checked prior to compressor engagement. If the switch opens, the ACM sets DTC B1348 and the message "VERY LOW REFRIGERANT - A/C COMPRESSOR OFF" will be displayed on the Driver Information Center (DIC). If a DTC B1348 is set, the compressor clutch will disengage and remain disengaged until DTC B1348 is cleared.

FAILURE CONDITIONS
1. Low refrigerant pressure switch remains open for several minutes.
2. Vehicle must be traveling above 30 mph of at least 30 seconds. This code may never set at idle or in city traffic.

ACTION TAKEN
1. Disables compressor until DTC is cleared.
2. Displays "VERY LOW REFRIGERANT - A/C COMPRESSOR OFF" message on DIC.

TEST DESCRIPTION
1. Check current state of low pressure switch.
2. Check circuits to low pressure switch.
3. Check HVAC refrigerant system pressure.
4. Check for a restriction in refrigerant system.
5. Check for intermittent short or open.