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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Seville - RHD 🢒 DTC 🢒 DTC B1330 Left A/C Discharge Sensor Fault

Object Number: 298487 Size: MF
HVAC Air Delivery/Temperature Control Schematics Temperature Sensors
HVAC Air Delivery/Temperature Control Schematics Temperature Sensors
HVAC Schematic Icons

Circuit Description

The left A/C temperature sensor is a thermistor that controls signal voltage to the Instrument Panel Integration Module (IPM). The IPM applies voltage on circuit 516. When the sensor is cold, the resistance is high and the IPM will sense a high signal voltage at terminal B6, connector C2. When the sensor warms, resistance is reduced and the signal voltage is pulled low through circuit 61. Signal voltage will vary from 5 V (open circuit) to 0 V (short circuit).

Conditions for Setting the DTC
    • The ignition is ON.
    • Circuit open or shorted.

Action Taken When the DTC Sets
    • A default value of 128 counts and 24°C (75°F) will be used by the IPM.
    • The default valve allows the system to operate.

Conditions for Clearing the MIL/DTC
    • Using a scan tool.
    • A current DTC will clear when the diagnostic runs and does not fail.
    • IPM battery voltage is interrupted.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step determines whether the Body Control Module (BCM) Diagnostic System Check was performed.

    2.

  2. This step ensures that the DTC was not set in error.

    3.

  3. This step determines whether the cause of the malfunction is the sensor, or an open or a short in a circuit.

    4.

  4. The scan tool verifies proper sensor operation. Clear all the DTCs after the repair procedure is complete.

Step

Action

Value(s)

Yes

No

1

Was the BCM diagnostic system check performed?

--

Go to Step 2

Go to Diagnostic System Check - Body Control System

2
  1. Turn the ignition ON.
  2. Disconnect the sensor.
  3. Measure the voltage between sensor harness connector terminal A and B.

Is the voltage within the specified range?

4.5-5.5 V

Go to Step 3

Go to Step 4

3

  1. Turn the ignition OFF.
  2. Reconnect the sensor.
  3. Connect the scan tool.
  4. Turn the ignition ON.
  5. Clear the DTC using the scan tool.
  6. Start the engine.

Did DTC reset?

--

Go to Step 4

Go to Intermittents and Poor Connections

4

  1. Select IPM open/short data on the scan tool.
  2. Display LH A/C temperature data.
  3. Start the engine.
  4. Unplug the LH A/C temperature sensor.
  5. The LH A/C temperature voltage increases to 5 V
  6. Reconnect the LH A/C temperature sensor connector.

Did the LH A/C temperature sensor voltage stay the same?

--

Go to Step 6

Go to Step 5

5
  1. Connect terminal A to ground.
  2. Measure the voltage between the IPM terminal B6 and ground

Is the specified voltage measured?

5 V

Go to Step 10

Go to Step 7

6

Replace sensor.

Refer to Air Conditioning (A/C) Temperature Sensor Replacement in HVAC Systems with A/C-Automatic.

Is the replacement complete?

--

Go to Step 12

--

7
  1. Remove the ground from terminal A.
  2. Measure voltage between sensor terminal A and ground.

Is the specified voltage measured?

5 V

Go to Step 8

Go to Step 10

8

Are all HVAC sensor DTCs present?

--

Go to Step 9

Go to Step 11

9

Inspect CK 61 (YEL) for an open between S223 and Connector C2, terminal B8.

If OK, replace the IPM. Refer to Body Control Module Replacement in HVAC Systems with A/C-Automatic.

Is the replacement complete?

--

Go to Step 12

--

10

Repair the open in CKT 516 (BLK).

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 12

--

11

Repair the open or short in CKT 61 (YEL) between terminal B8 and S223.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 12

--

12

  1. Using the scan tool, clear all the DTCs.
  2. Confirm proper operation of the A/C system.

Is the A/C system operating normally?

--

Go to Diagnostic System Check - Body Control System

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