What does it mean?
Code P0035 is a generic powertrain code that is used in both turbocharger and supercharger applications. When exhaust pressure builds up at the turbocharger/supercharger inlet, a pressure outlet hose on the turbocharger or supercharger directs excess pressure to the wastegate for release. On some boost solenoids, there may also be a vent to atmosphere or a bypass directly into the intake.
The bypass valve or boost solenoid actuates the wastegate at a certain pressure, allowing boost pressure to remain within the set allowances for the vehicle. It is controlled by the engine/powertrain control module (PCM). The boost solenoid or bypass valve is normally in the closed position. When pressure builds to the vehicle’s boost parameters, the solenoid switches, and the wastegate can be actuated to release pressure.
Should the solenoid fail to switch, excess pressure can cause turbocharger or engine damage from excess boost. However, if the solenoid remains in the open position, the turbocharger/supercharger’s inlet pressure will be insufficient to maintain proper boost for engine performance. DTC P0035 will be set in the PCM.
Note: Circuit High Input codes are mostly caused by defective alternators that develop excessive voltages, although there may be other causes as well, such as short circuits that “leak” current into a particular system from other, unrelated systems that work on higher voltages. Note that in the case of short circuits that leak power into a control circuit, there is likely to be other, seemingly unrelated trouble codes present along with the code(s) being investigated.
Diagnosing a “high input” code will always involve a thorough testing of the charging system as a first step, followed by measures to isolate the system from all other possible sources of power during resistance, continuity, and reference voltage tests.