20 A / 60 A DC (low amps) current clamp
PicoScope Battery Clip
*At Pico we are always looking to improve our products. The tools used in this guided test may have been superseded and the products above are our latest versions used to diagnose the fault documented in this case study.
The purpose of this test is to check the Gasoline Direct Injection (GDI) injector control voltage and current from an Engine Control Module (ECM).
This test involves measuring a potentially hazardous voltage.
Please ensure you follow manufacturers' safety instructions and working practices and ensure the rated voltage for all accessories you are using meets or exceeds the expected voltage.
To avoid possible damage to your scope, you may need to use an attenuator for this test.
Scopes with a 200 V range, such as PicoScope 4x25 models, do not need an attenuator for this test.
All other PicoScope Automotive models need an attenuator on the channel input. You can use either a 10:1 or a 20:1 attenuator provided that you adjust the PicoScope software accordingly. Select from the appropriate Channel Options menu:
View connection guidance notes.
The orientation of the clamp relative to the wire will determine whether it has a positive or negative output. If a live waveform does not appear on your screen, or appears to be inverted, try reversing the orientation of the clamp.
Injector feed and switched earth voltages and circuit current during engine cranking conditions.
Injector feed and switched earth voltages and circuit current during engine idle conditions.
Injector feed and switched earth voltages and circuit current during wide open throttle engine conditions.
Injector feed and switched earth voltages and circuit current during engine overrun conditions.
These known good waveforms have the following characteristics:
A GDI injector delivers fuel directly to the air charge within a cylinder.
The GDI injector fast reaction times enable an engine management system to operate across different cylinder charge modes, for example:
GDI injectors can deliver fuel with complex spray patterns and provide multiple injections per compression stroke. Furthermore, fuel can be kept from the cylinder volume until very close to the point of ignition reducing the risk of pre-ignition or knock and allowing the use of higher compression ratios, all of which leads to better thermal and fuel efficiencies.
As fuel injection coincides with the compression stroke, GDI injection pressures must be sufficient to overcome the in-cylinder pressures that occur across all engine load conditions. Therefore, GDI systems require a high pressure, up to 200 bar, fuel delivery system consisting of a common fuel rail supplied by a high-pressure fuel pump.
The ECM improves GDI injector response times by increasing the circuit voltage during the opening phase providing additional energy to move the valve rapidly. However, once the valve is fully open, only a relatively small voltage is necessary to hold it place, which the ECM maintains with a lower, pulsed, square wave voltage.
GDI injector failures may cause loss of engine performance, misfire or excessive smoking symptoms. Possible failure modes may be:
When operating out of their normal tolerances, for example, constant short runs or cold-start operation, GDI systems can cause the build-up of soot within the engine systems, which can cause a variety of secondary issues (e.g. blocked inlets, EGR valves, turbo vanes etc.). As such, regular maintenance is essential for continued operation within tolerances.
Selection of component related Diagnostic Trouble Codes (DTCs):
P0200 – Injector Circuit Malfunction
P0201 – Injector Circuit Malfunction – Cylinder 1
P0202 – Injector Circuit Malfunction – Cylinder 2
P0203 – Injector Circuit Malfunction – Cylinder 3
P0204 – Injector Circuit Malfunction – Cylinder 4
P0205 – Injector Circuit Malfunction – Cylinder 5
P0206 – Injector Circuit Malfunction – Cylinder 6
P0207 – Injector Circuit Malfunction – Cylinder 7
P0208 – Injector Circuit Malfunction – Cylinder 8
P0209 – Injector Circuit Malfunction – Cylinder 9
P0210 – Injector Circuit Malfunction – Cylinder 10
P0211 – Injector Circuit Malfunction – Cylinder 11
P0212 – Injector Circuit Malfunction – Cylinder 12
P0213 – Cold Start Injector 1 Malfunction
P0214 – Cold Start Injector 2 Malfunction
P0216 – Injection Timing Control Circuit Malfunction
P020A – Cylinder 1 Injection Timing
P020B – Cylinder 2 Injection Timing
P020C – Cylinder 3 Injection Timing
P020D – Cylinder 4 Injection Timing
P020E – Cylinder 5 Injection Timing
P020F – Cylinder 6 Injection Timing
P021A – Cylinder 7 Injection Timing
P021B – Cylinder 8 Injection Timing
P021C – Cylinder 9 Injection Timing
P021D – Cylinder 10 Injection Timing
P021E – Cylinder 11 Injection Timing
P021F – Cylinder 12 Injection Timing
P0261 – Cylinder 1 Injector Circuit Low
P0262 – Cylinder 1 Injector Circuit High
P0263 – Cylinder 1 Contribution/Balance Fault
P0264 – Cylinder 2 Injector Circuit Low
P0265 – Cylinder 2 Injector Circuit High
P0266 – Cylinder 2 Contribution/Balance Fault
P0267 – Cylinder 3 Injector Circuit Low
P0268 – Cylinder 3 Injector Circuit High
P0269 – Cylinder 3 Contribution/Balance Fault
P0270 – Cylinder 4 Injector Circuit Low
P0271 – Cylinder 4 Injector Circuit High
P0272 – Cylinder 4 Contribution/Balance Fault
P0273 – Cylinder 5 Injector Circuit Low
P0274 – Cylinder 5 Injector Circuit High
P0275 – Cylinder 5 Contribution/Balance Fault
P0276 – Cylinder 6 Injector Circuit Low
P0277 – Cylinder 6 Injector Circuit High
P0278 – Cylinder 6 Contribution/Balance Fault
P0279 – Cylinder 7 Injector Circuit Low
P0280 – Cylinder 7 Injector Circuit High
P0281 – Cylinder 7 Contribution/Balance Fault
P0282 – Cylinder 8 Injector Circuit Low
P0283 – Cylinder 8 Injector Circuit High
P0284 – Cylinder 8 Contribution/Balance Fault
P0285 – Cylinder 9 Injector Circuit Low
P0286 – Cylinder 9 Injector Circuit High
P0287 – Cylinder 9 Contribution/Balance Fault
P0288 – Cylinder 10 Injector Circuit Low
P0289 – Cylinder 10 Injector Circuit High
P0290 – Cylinder 10 Contribution/Balance Fault
P0291 – Cylinder 11 Injector Circuit Low
P0292 – Cylinder 11 Injector Circuit High
P0293 – Cylinder 11 Contribution/Balance Fault
P0294 – Cylinder 12 Injector Circuit Low
P0295 – Cylinder 12 Injector Circuit High
P0296 – Cylinder 12 Contribution/Balance Fault
This help topic is subject to changes without notification. The information within is carefully checked and considered to be correct. This information is an example of our investigations and findings and is not a definitive procedure. Pico Technology accepts no responsibility for inaccuracies. Each vehicle may be different and require unique test settings.
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