GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Seville 🢒 DTC 🢒 DTC P0532 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage

Object Number: 155155 Size: SF
Engine Controls Components
Cell 20: A/C Relay, A/C Pressure Sensor, CVRSS and EBTCM
OBD II Symbol Description Notice
ESD Notice

Circuit Description

The A/C Refrigerant Pressure sensor is a sensor that changes resistance based upon refrigerant pressure. The PCM provides a 5 volt reference and ground. The A/C refigerant sensor signal varies between ground and 5 volts as refrigerant pressure varies. As A/C refrigerant pressure increases, voltage increases. As A/C refrigerant pressure decreases, voltage decreases. A short to ground or open condition would cause the A/C refrigerant pressure sensor signal to go low, setting DTC P0532.

Conditions for Running the DTC
  1. Engine running.
  2. An A/C ON to Off transistion has not occured.

Conditions for Setting the DTC

The A/C refrigerant pressure sensor reading has been 0.10 volts or less.

Action Taken When the DTC Sets

    •  The Malfunction Indicator Lamp (MIL) will not illuminate.
    •  No message will be displayed.

Conditions for Clearing the MIL/DTC

    •  A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
    •  A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
    • Use a scan tool to clear DTCs.
    • Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. If the A/C refrigerant pressure sensor or circuitry are open, the A/C refrigerant pressure sensor parameter will read 0.0 to 0.10 volts.

    2.

  2. Checking if circuitry from sensor to PCM is able to respond to a 5 volt signal on the A/C refrigerant pressure input. A reading of 4.5 to 5.12 volts means wiring and PCM are OK.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn the key ON.
  2. Using a scan tool view the A/C refrigerant pressure sensor display.

Is the value displayed the same or less than the value specified?

0.10 volts

Go to Step 3

Fault not present.

3

  1. Turn the key to LOCK.
  2. Disconnect the A/C refrigerant pressure sensor.
  3. Jumper terminals C to B (harness side).
  4. Turn the key ON.

Is the value displayed higher than the value specified?

4.5 volts

Go to Step 14

Go to Step 4

4
  1. Remove the jumper.
  2. Using DMM J-39200 measure the voltage to ground at terminal B (harness side).

Is the voltage the same or higher than the voltage specified?

4.5 volts

Go to Step 5

Go to Step 7

5
  1. Record the fluid life indexes, turn the key to LOCK and wait 30 seconds.
  2. Disconnect PCM connector C1.
  3. Measure the resistance between PCM connector C1 terminal 56 and ground.

Is the resistance less than the value specified?

OL

Go to Step 10

Go to Step 6

6

Measure the resistance between PCM connector C1 terminal 56 and A/C refrigerant pressure sensor connector terminal C (harness side).

Is the resistance more than the value specified?

5 ohms

Go to Step 11

Go to Step 16

7
  1. View the TP Sensor display.
  2. Depress the accelerator pedal slightly.

Is the voltage higher than the value specified?

0.1 volts

Go to Step 8

Go to Step 9

8
  1. Record the fluid life indexes, turn the key to LOCK and wait 30 seconds.
  2. Disconnect PCM connector C1.
  3. Using DMM J 39200 measure the resistance between PCM connector C1 terminal 67 and A/C refrigerant pressure sensor terminal B.

Is the resistance more than the value specified?

5 ohms

Go to Step 12

Go to Step 16

9
  1. Record the fluid life indexes, turn the key to LOCK and wait 30 seconds.
  2. Disconnect PCM connector C1.
  3. Disconnect the TP sensor and the MAP sensor.
  4. Measure the resistance to ground at PCM connector C1 terminals 50 and 56 and 67.

Is the resistance less than the value specified?

OL

Go to Step 13

Go to Step 16

10

Repair the short to ground in the A/C refrigerant pressure sensor signal circuit.

Is the repair complete?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

--

11

Repair the open in the A/C refrigerant pressure sensor signal circuit.

Is the repair complete?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

--

12

Repair the open in the 5 Volt Reference circuit.

Is the repair complete?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

--

13

Repair short to ground in CKT(s) with low resistance.

Is the repair complete?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

--

14
  1. Check terminal contact at the A/C refrigerant pressure sensor.
  2. Repair terminal contact if needed.

Was terminal contact repaired?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

Go to Step 15

15

Replace the A/C refrigerant pressure sensor. Go to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement for repair instructions.

Is the replacement complete?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

--

16
  1. Check terminal contact at the PCM Connector C1 terminals 50, 56 and 67.
  2. Repair terminal contact if needed.

Was terminal contact repaired?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

Go to Step 17

17

Replace the PCM. Refer to Powertrain Control Module Replacement .

Is the replacement complete?

--

Go to Powertrain Control Module Diagnosis for Verify Repair

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