LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 2008 >> Optra LS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 1.6L >> Diagnostic Information and Procedures >> DTC P1504 >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

  1. Ignition ON, attempt to establish communication with the TCM with a scan tool.
  2. Ignition OFF, disconnect the harness connector at the TCM.
  3. Ignition ON, test for 1.5-3.4 volts between the CAN serial data low circuit terminal A7 and the CAN serial data high circuit terminal A17.
    • If not within the specified range, test the CAN communication circuits between the ECM and the TCM for an open, short to ground, or a short to voltage.
    • If the circuit tests normal, replace the ECM.
  4. If the circuits test normal, replace the TCM.
scientia non olet · About LEMON Manuals