For 1990-2009 cars

#### A/C System Pressure -- Zone Classification

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Were you sent here from the Cooling Insufficient, A/C System diagnostic table? | -- | Go to Step 2 | Go to Cooling Insufficient - Air Conditioning (A/C) System
2 | Visually inspect for restricted air flow at the condenser. Is the air flow through the condenser restricted | -- | Go to Step 3 | Go to Step 4
3 |

1. Repair the condition (air flow restriction) or replace the condenser, if damaged.
2. If replacement of the condenser is necessary, recover the refrigerant, then refer to Condenser Replacement .
3. Evacuate and charge the refrigerant system.
4. Leak test the refrigerant system.

Refer to Leak Testing .

Is the repair complete?

--

Go to Step 4

--

4 |

1. Start the engine and allow the engine to idle.
2. Turn ON the A/C, using the A/C button.
3. Inspect for proper cooling fan operation. Refer to Electric Cooling Fan Diagnosis in Engine Controls.

Are the cooling fans ON and operating properly?

--

Go to Step 6

Go to Step 5

5 | Repair the cooling fan operation fault. Refer to Electric Cooling Fan Diagnosis in Engine Controls. Is the repair complete? | -- | Go to Step 10 | --
6 |

1. The engine still idling in PARK.
2. The A/C still turned ON.
3. Feel the liquid line on both sides of the expansion (orifice) tube.

Is the temperature the same before and after the orifice?

--

Go to Step 7

Go to Step 8

7 |

1. Recover the refrigerant.
2. Replace the damaged/faulty expansion (orifice) tube (orifice opening too large and/or the O-ring is damaged or missing).

Refer to Expansion (Orifice) Tube Replacement .

Is the repair complete?

--

Go to Step 9

--

8 |

1. Air is in the refrigerant system, or the system is overcharged.
2. Recover the refrigerant.
3. Evacuate the refrigerant system.
4. Charge the refrigerant system to specifications.

Is the repair complete?

--

Go to Step 10

--

9 |

1. Evacuate and charge the refrigerant system.
2. Leak test the refrigerant system.

Refer to Leak Testing .

Are the operations completed?

--

Go to Step 10

--

10 |

1. Start the engine and allow the engine to idle.
2. An accurate thermometer still installed to the I/P center air outlet.
3. Set the HVAC control head to the following positions:

• | A/C button to ON

• | Temperature control to full cold

• | Mode control knob to UPPER (I/P outlets)

• | Blower switch to 5 (high)

4. Elevate and maintain the engine speed at 2000 RPM.
5. Allow the low and high side pressure readings to stabilize, if necessary.

(Stabilization usually requires 2-3 minutes.)

6. Record the low and high pressure readings and the delivered air output temperature.
7. Compare the low and high side pressures and the output temperatures to those listed in the A/C System Performance Chart.

Refer to System Performance Test .

Are both the low and high side pressures as well as the output temperatures within specifications?

--

Go to HVAC System Check

--