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Home >> Toyota >> 2003 >> Matrix Base, 4WD >> Repair and Diagnosis (Single Page) >> External Pages >> Different car >> Section 15 (Engine Control System Self-Diagnostics) >> Diagnostic Tests >> DTC P1637: ESTP Signal Malfunction >> Circuit Description
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Circuit Description

WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

The Hybrid Vehicle Electronic Control Unit (HV ECU) communicates with the ECM over the ESTP circuit. DTC is set when communication between HV ECU and ECM is interrupted for 2 seconds or more. Possible causes are: