DTC P1640, P1650, or P1660. Buick Rendezvous

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2006 🢒 Rendezvous - FWD 🢒 Accessories 🢒 Navigation Systems 🢒 DTC P1640, P1650, or P1660

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provide an overview of each diagnostic category.

DTC Descriptors

DTC P1640: Control Module Output A Circuit

DTC P1650: Control Module Output B Circuit

DTC P1660: Control Module Output C Circuit

The output driver module (ODM) is a control chip inside of the powertrain control module (PCM). The PCM contains multiple ODMs. ODMs provide grounded output control of devices. 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.

Conditions for Running the DTC

•	The ignition is ON.

•	The system voltage is between 9-11 volts.

Conditions for Setting the DTC

•	The PCM has detected a voltage greater than 26.5 volts.

•	Excessive current is detected on any circuit to the ODM.

•	The above conditions are present for 30 seconds.

Action Taken When the DTC Sets

•	The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

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The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

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

A condition with the charging system may cause this DTC to set. Refer to Charging System Test .

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

•	Powertrain Control Module Connector End Views

•	Engine Controls Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Verification

With the ignition ON, observe the Output Driver Status with a scan tool. All parameters should indicate OK or no fault present.

Circuit/System Testing

Observe the scan tool for any other DTCs.

⇒	If DTC P0560 is also set, refer to DTC P0560 to repair the charging system.

Observe the Output Driver Status with a scan tool.

⇒	If any parameter does NOT indicate OK, test for a short to voltage on the control circuit of the component that indicated a fault.

⇒	If all circuits test OK, replace the PCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PCM replacement, programming, and setup