DTC P1640: Control Module Output Circuit: Description
WARNING: This page is about a different car, the 2003 Saturn LW200 and 2003 Saturn L200. However, it is still accessible from the selected car via links, so may be relevant.
The PCM contains an Output Driver Module (ODM) that controls the following devices:
- A/C relay
- 1-2 shift solenoid
- 2-3 shift solenoid
- Torque Converter Clutch (TCC) solenoid
The ODM provides grounded output control of these devices through separate control circuits. The ODM monitors the voltage level at each of the control circuits when the device is commanded ON or OFF. Each ODM output has an internal feedback circuit that connects to the PCM microprocessor. The PCM monitors voltage through the ignition 1 voltage circuit. Excessive voltage or current may cause damage to the PCM. If the ODM detects excessive current or voltage on an output control circuit, this DTC will set.