P0236

DTC P0236 Turbocharger (TC) Boost System










Circuit Description

The PCM operates a solenoid to control boost. This solenoid is normally open. By providing a ground path the PCM energizes the solenoid which then allows vacuum to pass to the waste-gate valve. During normal operation, the PCM compares its wastegate duty cycle signal with the boost signal and makes corrections in the duty cycle accordingly. This is a type B DTC.

Conditions for Setting the DTC

^ Engine speed greater than 2400 RPM.
^ Fuel rate greater than 20 mm.
^ Boost pressure less than or equal to 20 kPa from desired (internal to PCM).
^ Conditions met for 10 seconds.
or
^ Engine speed greater than 1800 but less than 2400 RPM.
^ Fuel rate greater than 20 mm.
^ Boost pressure less than or equal to (110 kPa) - ((100 kPa Baro)/2) (internal to PCM).
^ Conditions met for 2 seconds.

Action Taken When the DTC Sets

^ Poor performance.
^ Reduce maximum fuel.
^ No TCC.

Conditions for Clearing the MIL/DTC

^ The PCM will turn the MIL off after three consecutive trips without a fault condition.
^ A History DTC will clear when forty consecutive warm-up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (160°F) that same ignition cycle).
^ Use of a Scan Tool.

Diagnostic Aids

A vacuum leak or a pinched vacuum line may cause a DTC P0236. Check all vacuum lines and components connected to the hoses for leaks or sharp bends. Check vacuum source. A possible EGR DTC will store if there is a problem with the vacuum source. Also check for proper vacuum line routing. This diagnostic checks for a "skewed" sensor.

Test Description

Number(s) below refer to the number(s) on the diagnostic table.

This will check the Boost sensor scaling. One step will check the scaling with vacuum applied and one without.