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Donny
Donny, ASE Certified Technician
Category: Car
Satisfied Customers: 828
Experience:  A.S.E. Master Technician, Over 25 years working in Chrysler dealers, Top tech DaimlerChrysler 1998
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Fix jeep liberty code p1589 A/C Pressure Sensor Volts Too High

Customer Question

how do i fix jeep liberty code p1589 A/C Pressure Sensor Volts Too High
Submitted: 8 years ago.
Category: Car
Expert:  Donny replied 8 years ago.

Hello

Do you mean P1598-A/C PRESSURE SENSOR VOLTAGE TOO HIGH do not see a1589 in the manual

1 Ensure the A/C refrigerant System is properly charged

Ignition on, engine not running.

With the Scan tool read codes and record the related Freeze Frame data.

Start the engine.

With the Scan tool, read the A/C Pressure Sensor voltage. Is the voltage above 4.9 volts?

Yes Go To 2

No INTERMITTENT CONDITION

2 Turn the ignition off.

Disconnect the A/C Pressure Sensor harness connector.

Connect a jumper wire between the (C18) A/C Pressure Signal circuit and the (K4)

Sensor ground circuit in the Sensor harness connector.

With the Scan tool, monitor the A/C Pressure Sensor voltage.

Ignition on, engine not running.

Is the voltage below 1.0 volt?

Yes Replace the A/C Pressure Sensor.

No Go To 3

NOTE: Remove the jumper wire before continuing.

3 Turn the ignition off.

Disconnect the PCM harness connectors.

Ignition on, engine not running.

Measure the voltage on the (C18) A/C Pressure Signal circuit in the A/C Pressure Sensor harness connector.

Is the voltage above 5.2 volts?

Yes Repair the short to voltage in the (C18) A/C Pressure Signal circuit.

No Go To 4

4 Turn the ignition off.

Measure the resistance of the (C18) A/C Pressure Sensor Signal circuit from the A/C

Pressure Sensor harness connector to the PCM harness connector.

Is the resistance below 5.0 ohms?

Yes Go To 5

No Repair the open in the (C18) A/C Pressure Signal circuit.

5 Measure the resistance between the (C18) A/C Pressure Signal circuit and the (K6)

5-volt Supply circuit in the A/C Pressure Sensor harness connector.

Is the resistance below 5.0 ohms?

Yes Repair the short between the (K6) 5-volt Supply circuit and the

(C18) A/C Pressure Signal circuit.

No Go To 6

6 Measure the resistance of the (K4) Sensor ground circuit from the A/C Pressure

Sensor harness connector to the PCM harness connector.

Is the resistance below 5.0 ohms?

Yes Go To 7

No Repair the open in the (K4) Sensor ground circuit.

7 NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

If there are no possible causes remaining, view repair.

Repair

Replace and program the Powertrain Control Module

I hope that this helps you, pin 19 of the white PCM conector is transducer signal

Thank you

Donny

A/C PRESSURE TRANSDUCER (GAS) - BLACK 4 WAY

CAVCIRCUITFUNCTION
1K4 SENSOR GROUND
2K6 5 VOLT SUPPLY
3C18 A/C PRESSURE SIGNAL