PicoScope 7 Automotive
Available for Windows, Mac, and Linux, the next evolution of our diagnostic scope software is now available.
Turbo testing
Turbo testing
Is there a test that I can do with my pico on a turbo, The car is a 1.6 cayc Leon, I hav e a fault code for overboost so I suspect the veins are sticking but when I actuate with vcds the actual and desired boost pressure match. The fault is intermittent but I would like to test to see in current test to see if there are any discrepancies before keeping the car for a few weeks to allow the fault to happen.
I will also add that I have checked the vacuum pipes and induction system for leaks and also understand the guided test for the turbo system but I need to understand what I should be looking for and how I could possibly replicate the fault?
I will also add that I have checked the vacuum pipes and induction system for leaks and also understand the guided test for the turbo system but I need to understand what I should be looking for and how I could possibly replicate the fault?
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Steve Smith
- Pico Staff Member
- Posts: 1591
- Joined: Sun Aug 25, 2013 7:22 am
Re: Turbo testing
Hello and thank you for the post.
Intermittent over boost can be challenging to capture given the numerous variables required to “align” in order to bring about the fault condition.
Prolonged road testing (often using the customer vehicle long term) would allow you to replicate all these variables whilst capturing live data; ideally with a 4 Channel Scope
The following case study describes one such technique here where a Turbo Position Sensor is utilized
Sorry I am not familiar with the SEAT Leon and whether a Turbo Position Sensor is applicable to this vehicle? (I will assume not at this stage)
Using the Case Study example in order to capture and qualify the over boost event I would choose
Channel A Gas Pedal Position sensor (Which provides driver intention)
Channel B Duty control of Turbo Vacuum Control solenoid (Assuming Vacuum control is applicable)
Channel C Boost Pressure Sensor Signal
Channel D WPS500 located in the vacuum hose the VNT Actuator
Here you will able to apply a Duty math channel to Channel B in order to graph the duty control of the vacuum control solenoid (PCM intention)
With all the above data captured (during the fault condition) you will have the following key pieces of information
1. Driver intention data, foot on/off gas pedal during over boost
2. PCM intention during over boost (did the PCM attempt to reduce boost)
3. Manifold “actual” pressure level during over boost (so supporting the fault code)
4. Vacuum level to the VNT actuator (confirming correct mechanical operation of the VNT Vacuum Control solenoid)
More information on Duty math can be found here
I hope some of these help in the interim, take care……Steve
Intermittent over boost can be challenging to capture given the numerous variables required to “align” in order to bring about the fault condition.
Prolonged road testing (often using the customer vehicle long term) would allow you to replicate all these variables whilst capturing live data; ideally with a 4 Channel Scope
The following case study describes one such technique here where a Turbo Position Sensor is utilized
Sorry I am not familiar with the SEAT Leon and whether a Turbo Position Sensor is applicable to this vehicle? (I will assume not at this stage)
Using the Case Study example in order to capture and qualify the over boost event I would choose
Channel A Gas Pedal Position sensor (Which provides driver intention)
Channel B Duty control of Turbo Vacuum Control solenoid (Assuming Vacuum control is applicable)
Channel C Boost Pressure Sensor Signal
Channel D WPS500 located in the vacuum hose the VNT Actuator
Here you will able to apply a Duty math channel to Channel B in order to graph the duty control of the vacuum control solenoid (PCM intention)
With all the above data captured (during the fault condition) you will have the following key pieces of information
1. Driver intention data, foot on/off gas pedal during over boost
2. PCM intention during over boost (did the PCM attempt to reduce boost)
3. Manifold “actual” pressure level during over boost (so supporting the fault code)
4. Vacuum level to the VNT actuator (confirming correct mechanical operation of the VNT Vacuum Control solenoid)
More information on Duty math can be found here
I hope some of these help in the interim, take care……Steve