GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 DeVille 🢒 DTC 🢒 DTC B1313 High Side Temp Sensor Short Circuit

Object Number: 506749 Size: MF
HVAC Components
HVAC Compressor Control Schematics (Cell 67: Temperature Sensors)
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice
HVAC Compressor Control Schematics
Power Distribution Schematics
Power Distribution Schematics

Circuit Description

The high side temperature sensor is a thermistor that controls the signal voltage to the heater and A/C programmer. The heater and A/C programmer supplies voltage on CKT 732. When the sensor is cold, the following conditions exist:

    • The resistance is high.
    • The heater and A/C programmer reads a high signal voltage at pin C5.

When the sensor warms, the following actions occur:

    • The resistance decreases.
    • The signal voltage is pulled low through CKT 407.

The signal voltage varies between 5 V (open circuit) and 0 V (short circuit).

Conditions for Running the DTC

Turn the ignition to the ON position. DTC B1310 is not set.

Action Taken When the DTC Sets
    • The high cooling fans operate when the A/C compressor operation is possible.
    • A default value of 79°C (144°F) is substituted in order to continue the operation of the system.

Notes on Intermittence

In some vehicles, this DTC may set intermittently if the sensor temperature falls below -1°C (30°F). The DTC will become history after the sensor temperature increases.

If an intermittent DTC B1313 is being set, use a Scan Tool in order to select the following settings:

    • Data list
    • Open/shorts data
    • Observe the reading

Manipulate the wiring while observing the Scan Tool . If a failure is induced, the reading will jump. Inspect for the following conditions:

    • Faulty terminal contact
    • An obstructed or defective sensor

Test Description

  1. Perform the Diagnostic System Check before continuing with the diagnosis of this DTC.

    2.

  2. The Scan Tool displays the high side temperature. Disconnecting the sensor determines if the wiring or the sensor is the cause.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check

2

  1. Turn the ignition to the ON position.
  2. Connect a Scan Tool .
  3. Disconnect the high side temperature sensor.

Did the DTC change from B1313 to B1312?

--

Go to Step 4

Go to Step 3

3
  1. Disconnect the heater and A/C programmer and the high side temperature sensor.
  2. Connect a test lamp between C5 and B+. Refer to Troubleshooting with a Test Lamp in Wiring Systems.

Does the test lamp light?

--

Go to Step 6

Go to Step 5

4
  1. Replace the high side temperature sensor. Refer to Temperature Sensor Replacement - High Side .
  2. Use the Scan Tool in order to clear the code.

Did you complete the repair?

--

Go to Diagnostic System Check

--

5
  1. Inspect the terminal contact. Refer to Testing for Electrical Intermittents in Wiring Systems.
  2. If the terminal contact is OK, replace the heater and A/C programmer. Refer to Programmer Replacement .
  3. Use the Scan Tool in order to clear the code.

Did you complete the repair?

--

Go to Diagnostic System Check

--

6
  1. Repair the short to ground in CKT 732. Refer to Wiring Repairs in Wiring Systems.
  2. Use the Scan Tool in order to clear the code.

Did you complete the repair?

--

Go to Diagnostic System Check

--