A/C - Works Erraticly or Suddenly Stops
NO.:24-13-92
GROUP:
Air Conditioning
DATE:
Nov. 16, 1992
SUBJECT:
Air Conditioning Pressure Transducer
MODELS:
1993 (LH) Concorde/Intrepid/Vision
SYMPTOM/CONDITION:
Some vehicles may have a faulty A/C pressure transducer. The symptoms are the following:
^ A/C works only some of the time, i.e., sometimes cold air, and sometimes warm air coming from the outlets.
^ A/C was working but suddenly stopped.
DIAGNOSIS:
The diagnosis should be performed in the order described below. If at any time the criteria indicated with "#" is met, turn off the vehicle and refer to the "REPAIR PROCEDURE" section of this document.
^ Start engine and let idle (approx. 700 RPM) with transaxle in park and A/C off .
^ Observe A/C pressure reading with DRBII (scan tool), and a pressure gage set attached to the service ports on the A/C compressor manifold. To monitor pressure on the DRBII, enter the following commands: "4) Select System", "9) Climate Control", "3) State Display", "4) Monitors" and "1) No A/C Clutch". Note pressure reading for future reference.
# - If the DRBII indicates a pressure near 0 or 500 PSI and the high side gage does not show the same pressure, the pressure transducer (or connector) is suspect.
- If both the DRBII and high side gage indicate a pressure near 30 PSI or below, check system for low refrigerant charge before repeating diagnosis procedure.
^ Use a long rod, such as a three (3) foot long 3/8 inch dowel, to jiggle the transducer at electrical connection area. BE CAREFUL TO AVOID ALL MOVING PARTS - BODILY HARM OR DAMAGE TO THE VEHICLE CAN OCCUR IF THIS PRECAUTION IS NOT TAKEN.
- A pressure variation of 1 or 2 PSI is normal during this procedure.
# - Pressure jumps to near 0 or 500 PSI are an indication of a faulty pressure transducer (or connector).
^ Set the A/C controls as follows:
- A/C controls set to outside air
- Panel mode
- Full cool (full counter-clockwise position)
- Low blower (one notch clockwise from "OFF" position)
- A/C button in the "ON" position
- Vehicle windows open
- Recirc button turned OFF on Automatic Temperature Control (ATC) equipped vehicles
^ Observe compressor clutch for normal cycling.
- If A/C system pressure is above 30 PSI and below 430 PSI and clutch doesn't engage, the transducer is not the problem. Perform usual A/C diagnosis to resolve.
^ Monitor A/C system pressure with DRBII.
# - If pressure reading does not increase during compressor clutch 'on' periods, tranducer is suspect.
^ Adjust A/C blower controls to high setting (full clockwise rotation).
^ Let system run a couple of minutes to stabilize.
^ Use previously mentioned rod to jiggle transducer while compressor clutch remains engaged.
BE CAREFUL TO AVOID ALL MOVING PARTS - BODILY HARM OR DAMAGE TO THE VEHICLE CAN OCCUR IF THIS PRECAUTION IS NOT TAKEN.
- The pressure reading should remain in the normal operating range with minor pressure fluctuations occurring.
# - Unusual pressure jumps (for example - 50 PSI) are an indication of a faulty transducer (or connector).
PARTS REQUIRED:
1 Transducer - A/C Fan and Pressure w/O-Ring 4723028
AR Connector Pigtail - A/C Transducer 4728323
REPAIR PROCEDURE:
This repair procedure involves replacing the A/C pressure transducer and wiring if required.
^ With vehicle off, disconnect the transducer wiring connector and examine it for damage.
- If no wiring damage is observed, remove and replace the pressure transducer, per the service manual instructions. Torque to 6 N-m (50 in. lbs.).
^ Repeat the diagnostic procedure to verify that the A/C system functions properly.
- If a problem persists, replace the wiring connector following package instructions.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No.
Replace A/C Pressure Transducer 24-35-71-90......0.3 Hrs.
Replace Transducer & Wiring 24-35-71-91........0.5 Hrs.
FAILURE CODE:
61 - Intermittent Operation