GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Malibu 🢒 DTC 🢒 DTC P1682

Circuit Description

The Throttle Actuator Control (TAC) System uses an ignition voltage supply separate from the powertrain control module (PCM) supply. If the PCM detects a voltage difference between the two circuits, DTC 1682 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1682 Ignition 1 Switch Circuit 2

Conditions for Running the DTC
    • The ignition is ON.
    • DTC P1682 runs continuously once the ignition is ON.

Conditions for Setting the DTC

The ignition 1 voltage is less than 10 volts for more than 2 seconds.

Action Taken When the DTC Sets
    • The control module stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
    • The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC
    • A current DTC Last Test Failed clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
    • Clear the DTC with a scan tool.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Observe the Freeze Frame/Failure Records data for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Turn ON the ignition, with the engine OFF for 10 seconds.

Does the DTC fail this ignition?

--

Go to Step 3

Go to Intermittent Conditions

3

With a test lamp connected to ground, probe both sides of the electronic temperature control (ETC) fuse.

Does the test lamp illuminate on both sides of the fuse?

--

Go to Step 5

Go to Step 4

4

Does the test lamp illuminate on one side of the fuse?

--

Go to Step 6

Go to Powertrain Relay Diagnosis

5
  1. Turn OFF the ignition.
  2. Disconnect the powertrain control module (PCM).
  3. Test the ignition 1 voltage circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 7

6

  1. Turn OFF the ignition.
  2. Disconnect the PCM.
  3. Test the ETC run/crank voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  4. Replace the fuse if necessary.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 7

7

Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

8

Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 9

--

9
  1. Use a scan tool to clear the DTCs.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze/Frame Failure Records.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 10

10

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK