GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Optra 🢒 HVAC 🢒 HVAC - Automatic 🢒 DTC 3

Conditions For Setting The DTC

This DTC code will set if the output of the coolant sensor indicates a probable short circuit or an open in the sensor or the associated wiring harness, or a malfunction of the automatic temperature control (ATC) controller.

Step

Action

Value(s)

Yes

No

1
  1. Disconnect the coolant temperature sensor connector from the automatic temperature control (ATC) harness.
  2. Inspect the wiring from the sensor to the connector and examine the connector for any signs of damage.
  3. Measure the resistance between the coolant temperature sensor connector terminals.

Is there any sign of damage in the wiring or connector, or is the resistance measured outside the specified range at 20-25°C (68-77°F)?

2600-2100 ohms

Go to Step 2

Go to Step 3

2

Repair the damaged wiring or the connector, or replace the coolant temperature sensor as required.

Did you find and correct the condition?

--

System OK

--

3
  1. Turn the ignition to ON.
  2. Measure the voltage between the 2 coolant temperature sensor connector terminals on the ATC harness.

Is the voltage measured less than or equal to the specified value?

4 V

Go to Step 7

Go to Step 4

4

Inspect the terminals on the coolant temperature sensor connector.

Is any problem found with the connector?

--

Go to Step 5

Go to Step 6

5

Repair the connector terminals or replace the coolant temperature sensor or ATC controller as required.

Did you find and correct the condition?

--

System OK

--

6
  1. Connect the coolant temperature sensor to the ATC harness.
  2. Turn the ignition switch to ON.
  3. Observe the temperature display area.

Does this display indicate the continuing presence of a code 3 condition?

--

Go to Step 9

System OK

7
  1. Pull the ATC controller from the instrument panel, leaving the wiring harness connected.
  2. Measure the voltage between terminals A13 and B9 by backprobing the connectors.

Is the voltage measured less than or equal to the specified value?

4 V

Go to Step 9

Go to Step 8

8
  1. Test the wiring from controller terminals A13 and B9 to the coolant temperature sensor connector terminals on the ATC harness connectors.
  2. Repair any open or high resistance found in the wiring or connector terminals.

Did you find and correct the condition?

--

System OK

--

9

Replace the ATC controller.

Did you complete the replacement?

--

System OK

--