Code Definition

P0959 — ASM Mode Circuit Intermittent

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0959

P0959 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0959 is stored, the module has detected an electrical-circuit fault in the wiring, connector, or driver associated with the named component.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0959 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The P0959 fault code is triggered when the control module detects intermittent signals in the ASM (Adaptive Shift Control) mode circuit. This circuit is integral to the operation of different transmission modes like performance, winter, or sport, which adjust the transmission's shifting patterns according to various driving preferences and conditions. An intermittent fault in the ASM mode circuit suggests sporadic or inconsistent signals, which can be due to issues like loose connections, corroded terminals, intermittent shorts in the wiring, or problems within the mode selection components li...

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