QuestionI think you may have addressed this previously, but I need to know the correct (hopefully least cost) remedy for the following DTC codes (P0236 Turbo/Super Charger Boost Sensor "A" Circuit Range/Performance and P0237 Turbo/Super Charger Boost Sensor "A" Circuit Low). Greatly appreciated!
AnswerC,
Diagnostic trouble code (DTC) ECM-170F/P0236 is stored if the boost pressure sensor's registered pressure deviates from the atmospheric pressure sensor's registered pressure. This comparison is made at engine start (at approximately 500 rpm ) before the turbocharger (TC) has built up a boost pressure.
Substitute Value
Possible Source
Faulty Signal
contact resistance in terminals
defective boost pressure sensor
defective atmospheric pressure sensor
ECM-1600/P0237 Boost Pressure Sensor
Condition
Diagnostic trouble code (DTC) ECM-1600/P0237 (signal too high or too low) is stored if the signal from the boost pressure sensor is outside its normal range. The fault is diagnosed by the control module when the ignition is on/the engine is running.
Diagnostic trouble code (DTC) ECM-1600 (faulty signal) is stored if the signal from the boost pressure sensor is within its normal range but deviates from the calculated boost pressure. The fault is diagnosed by the control module when the engine is running.
Substitute Value
Limited boost pressure (if the signal is too high).
Possible Source
Signal Too High:
Contact resistance in the terminals
Short-circuit to supply voltage in the signal cable
Open-circuit in the signal cable
Defective boost pressure sensor.
Signal Too Low:
Short-circuit to ground in the signal cable
Defective boost pressure sensor.
Faulty Signal:
The boost pressure sensor has come loose
Contact resistance in the terminals
Defective boost pressure sensor.
Fault Symptom[s]
Malfunction indicator lamp (MIL) lit
Poor performance.
What you supplied are "generic fault codes". Better codes might be read using the Volvo scan tool, it will give a better idea of the fault. I have seen just a vacuum leak in the system of one or more lines or intercooler hoses set various codes. If using the Volvo scan tool you can take reading of the sensors and see if they are working or just staying steady, that would give you a better idea if the sensor is faulty or to look for vacuum leaks. If the engine has too high crankcase pressure because of the breather box blocked of defective valve in it that can cause some fuel trim fault codes. Volvo uses a vacuum pressure gauge on the oil dip stick tube to measure the pressure. As for cost no idea, just have to spend the time and find the faults.
