GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2009 🢒 Vibe - AWD 🢒 HVAC 🢒 HVAC - Manual 🢒 DTC B1413

Circuit Description

The evaporator temperature sensor (A/C thermistor) is installed on the evaporator in the air conditioning unit. The A/C thermistor detects the temperature of the cooled air passed through the evaporator. Its signal is sent to the A/C amplifier and is used to control the air conditioning. The resistance of the A/C thermistor changes in accordance with the temperature of the cool air passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The A/C amplifier applies 5 volts to the A/C thermistor and reads the voltage changes as the resistance of the A/C thermistor changes. This sensor is used to prevent the evaporator from freezing.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1413 Evaporator Temperature Sensor Circuit

Conditions for Running the DTC

This DTC shall run when the ignition is On.

Conditions for Setting the DTC

An open or short in the evaporator temperature sensor circuit.

Action Taken When the DTC Sets

The A/C compressor will be disabled.

Conditions for Clearing the DTC

The DTC will clear when conditions for setting the DTC have been repaired.

Step

Action

Value(s)

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: Component Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, observe the Evaporator Temp Sensor parameter in the HVAC data list.

Does the Evaporator Temp parameter display the current evaporator temperature?

--

Go to Step 3

Go to Step 6

3

  1. Turn OFF ignition.
  2. Disconnect the evaporator temperature sensor.
  3. Measure the resistance between connector E67 terminal 1 and terminal 2 at -10°C (14°F), -5°C (23°F), 0°C (32°F), 5°C (41°F), 10°C (50°F), 15°C (59°F), 20°C (68°F), 25°C (77°F), and 30°C (86°F).

Is the resistance measured within the specified values?

-10°C (14°F) = 7.30 - 9.10 Kohms

-5°C (23°F) = 6.65 - 6.95 Kohms

0°C (32°F) = 4.40 - 5.35 Kohms

5°C (41°F) = 3.40 - 4.15 Kohms

10°C (50°F) = 2.70 - 3.25 Kohms

15°C (59°F) = 2.14 - 2.58 Kohms

20°C (68°F) = 1.71 - 2.05 Kohms

25°C (77°F) = 1.38 - 1.64 Kohms

30°C (86°F) = 1.11 - 1.32 Kohms

Go to Step 4

Go to Step 7

4
  1. Disconnect the A/C amplifier connector.
  2. Measure the resistance between the A/C amplifier connector E62 terminal 10 and the evaporator temperature sensor connector E67 terminal 1, the A/C amplifier connector E62 terminal 11 and the evaporator temperature sensor connector E67 terminal 2, the A/C amplifier connector E62 terminal 10 and body ground, and the A/C amplifier connector E62 terminal 11 and body ground.

Does the resistance measure within the specified values?

Between E62 terminal 10 and E67 terminal 1 = Below 1 Ohm

Between E62 terminal 11 and E67 terminal 1 = Below 1 Ohm

Between E62 terminal 10 and body ground = 11 Kohm or higher

Between E62 terminal 11 and body ground = 10 Kohm or higher

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Go to Step 6

Go to Step 5

5

Repair or replace harness or connector between the ambient temperature sensor and instrument panel.

Did you complete the repair or replacement?

 

Go to Step 8

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6

Replace the A/C amplifier.

Did you complete the replacement?

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Go to Step 8

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7

Replace the evaporator temperature sensor.

Did you complete the replacement?

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Go to Step 8

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8
  1. Use the scan tool in order to clear the DTC.
  2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

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Go to Step 2

System OK