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Home >> Toyota >> 2003 >> Matrix Base, FWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 103 (Engine Control System Self Diagnostics) >> Diagnostic Tests >> DTC P1646: Transmission Control Ecu Malfunction >> Possible Causes
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Possible Causes

WARNING: This page is about a different car, the 2003 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.

DTC is set when no communication from transmission control Electronic Control Unit (ECU) is detected. Possible causes are: