GM Service Manual Online
For 1990-2009 cars only

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 provides an overview of each diagnostic category.

DTC Descriptors

DTC P1663: Change Engine Oil Lamp Control Circuit

DTC P1663 01: Change Engine Oil Lamp Control Circuit Short to Battery

DTC P1663 02: Change Engine Oil Lamp Control Circuit Short to Ground

DTC P1663 04: Change Engine Oil Lamp Control Circuit Open Circuit

DTC P1663 54: Change Engine Oil Lamp Control Circuit Temperature High

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Voltage Supply

P1663, P1663 02

P1663, P1663 04

--

--

Control Circuit

P1663, P1663 02

P1663, P1663 04

P1663, P1663 01

P1663 54

Circuit/System Description

The change engine oil lamp is located on the instrument panel cluster (IPC). The lamp informs the driver if an engine oil change is required. The engine control module (ECM) monitors the lamp control circuit for conditions that are incorrect for the commanded state of the lamp. For example, a failure condition exists if the ECM detects low voltage when the lamp is commanded OFF, or high voltage when the lamp is commanded ON.

Conditions for Running the DTC

    • The ignition is ON.
    • The ignition voltage is between 8.5-16.5  volts.
    • DTC P1663 runs continuously once the above conditions are met.

Conditions for Setting the DTC

P1663 01

The ECM detects a short to voltage on the circuit that controls the lamp.

P1663 02

The ECM detects a short to ground on the circuit that controls the lamp.

P1663 04

The ECM detects an open on the circuit that controls the lamp.

P1663 54

The ECM detects that the internal output driver is over temperature.

Action Taken When the DTC Sets

DTC P1663 is a Type C DTC.

Conditions for Clearing the DTC

DTC P1663 is a Type C DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, command the lamp ON and OFF with a scan tool. The lamp should turn ON and OFF as commanded.

Circuit/System Testing

  1. If any other IPC indicators or gages are inoperative, refer to Symptoms - Displays and Gages.
  2. Ignition OFF, disconnect the ECM harness connectors. Ignition ON, the lamp should not illuminate.
  3. If the lamp is illuminated, test the lamp control circuit for a short to ground. If the circuit tests normal, replace the IPC.
  4. Ignition ON, connect a 3A fused jumper wire between the lamp control circuit and ground. The lamp should illuminate.
  5. If the lamp does not illuminate, test the lamp control circuit for a short to voltage, or an open/high resistance. If the circuit tests normal, replace the IPC/bulb.
  6. If all circuits test normal, replace the ECM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Instrument Cluster Replacement
    •  Instrument Cluster Bulb Replacement
    •  Control Module References for engine control module replacement, setup, and programming