GM Service Manual Online
For 1990-2009 cars only

Circuit Description

Output driver modules (ODM) are chips that are inside the powertrain control module (PCM). ODMs provide grounded outputs that control devices. Each output has an internal feedback circuit that connects to the PCM microprocessor. ODM 3 determines if the voltage or the current may cause damage to the PCM. The PCM monitors voltage through the ignition 1 input. Any incorrect current that is on a circuit to the ODM will cause the ODM to report this DTC.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

    • The ODM has detected a voltage more than 33 volts.
    • Excessive current is detected on any circuit to the ODM.
    • The conditions are present for 30 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.

Diagnostic Aids

An over charging condition may set this DTC. Refer to Diagnostic System Check - Engine Electrical in Engine Electrical.

Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Repair the circuits as necessary. Refer to Intermittent Conditions .

DTC P1660 Control Module Output C Circuit

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Is DTC P0560 set?

Go to Diagnostic System Check - Engine Electrical in Engine Electrical

Go to Step 3

3

  1. With a scan tool select the Output Driver Data list.
  2. Observe the parameters on the scan tool.

Do any parameters indicate a fault present?

Go to Step 4

Go to Step 5

4

Test for a short to voltage on the control circuit of the component that indicated a fault.

Did you find and correct the condition?

Go to Step 6

Go to Step 5

5

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

Go to Step 6

--

6

  1. Using the scan tool, clear the DTCs.
  2. Start the engine.
  3. Allow the engine to idle until the engine reaches normal operating temperature.
  4. Select DTC and the Specific DTC function.
  5. Enter the DTC number which was set.
  6. Operate the vehicle, with the Conditions for Setting the DTC, until the scan tool indicates the diagnostic Ran.

Does the scan tool indicate that the diagnostic Passed?

Go to Step 7

Go to Step 2

7

Does the scan tool display any additional undiagnosed DTCs?

Go Diagnostic Trouble Code (DTC) List

System OK