GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Epica 🢒 Engine 🢒 Engine Controls - 2.0L (L34 GMDAT) 🢒 DTC 006

Circuit Description

The low speed cooling fan relay is controlled by the electronic control module (ECM). The ECM applies a ground to the low speed cooling fan relay to achieve low speed cooling fan operation. The ECM determines when to activate the low speed cooling fan relay depending on the coolant temperature and the A/C system high side pressure.

Conditions for Setting the DTC
    • A short to battery voltage condition exists.
    • This condition is present for more than 2 seconds.

Diagnostic Aids

An intermittent problem may be caused by a poor connection, rubbed through wire insulation, or a broken wire inside the insulation.

Step

Action

Values

Yes

No

1

Determine whether the Diagnostic System Check has been performed.

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Inspect the fuse F3.

Is the fuse in good condition?

--

Go to Step 4

Go to Step 3

3
  1. Replace the fuse.
  2. Clear any DTCs from the engine control module (ECM).
  3. Perform the Diagnostic System Check.

Is the repair complete?

--

System OK

--

4
  1. Disconnect the ECM connector.
  2. Disconnect the high speed cooling fan relay.
  3. Measure the voltage between the ECM connector terminal A14 and ground.

Does the voltage measure within the value specified?

0 V

Go to Step 6

Go to Step 7

5
  1. Repair the short to voltage between the high speed cooling fan relay connector terminal 85 and the ECM connector terminal A14.
  2. Clear any DTCs from the ECM.
  3. Perform the Diagnostic System Check.

Is the repair complete?

--

System OK

--

6

Measure the resistance between the high speed cooling fan relay terminals 86 and 85.

Does the resistance measure near the value specified?

0 ohms

Go to Step 7

Go to Step 8

7
  1. Replace the high cooling fan relay.
  2. Clear any DTCs from the ECM.
  3. Perform the Diagnostic System Check.

Is the repair complete?

--

System OK

--

8

Inspect for a short to voltage or open in the wiring between the following:

    • I/P fuse block C201 connector terminal 1 and high speed cooling fan relay connector terminal 86
    • Positive battery wiring harness and high speed cooling fan relay connector 30
    • High speed cooling fan relay connector terminal 87 and main cooling fan motor connector terminal 2

Is the problem found?

--

Go to Step 9

Go to Step 10

9
  1. Repair the short to voltage or open in the wiring.
  2. Clear any DTCs from the ECM.
  3. Perform the Diagnostic System Check.

Is the repair complete?

--

System OK

--

10

Inspect for a poor connection at the ECM connector terminal A14.

Is the problem found?

--

Go to Step 11

Go to Step 12

11
  1. Repair or replace the connector terminal as needed.
  2. Clear any DTCs from the ECM.
  3. Perform the Diagnostic System Check.

Is the repair complete?

--

System OK

--

12
  1. Replace the ECM. Refer to Engine Control Module Replacement .
  2. Perform the Diagnostic System Check.

Is the repair complete?

--

System OK

--