The purpose of this test is to check the current for a piezo diesel injector under different operating conditions.
Connection for diagnostic work will vary dependent on application.
Technicians should whenever possible gain access to the test circuit without damage to seals and insulation. If this is not possible then make sure appropriate repairs are completed.
General connection advice
PicoScope offers a range of options within the test kits.
Dependent on difficulty of access, choose from:
Testing sensors and actuators (to include relevant circuit/connectors):
Note: If the waveform does not start with a positive pulse, the current clamp has been connected the wrong way around. Remove it and replace facing the opposite direction.
These example waveforms show the injector current during different operating conditions.
The positive signals are the injector open commands and the negative signals are the injector close commands. Therefore the time between the positive peak and the negative peak is the injector on time controlled by the Engine Control Module (ECM).
Example 1: The first two injector phases are pre-injection and the third is the main injector phase.
Example 2: As the engine speed is raised the ECM increases the duration of the main injector phase.
Example 3: On over-run only the first pilot injection phase remains.
Piezo injectors have the advantage over conventional electromagnetic injectors of a very quick reaction time up to four times faster.
Piezo injectors operate using of a stack of about 300 thin piezo ceramic plates. When the switching voltage is applied the plates expand opening the needle and allowing pressurised fuel into the cylinder.
As with all common-rail systems, there may be various injection phases.
Figure 3 shows a piezo element in its two different states. Illustration 1 shows the stack with no supply voltage and illustration 2 shows the increase in height of the stack when the supply voltage is switched on.
Note: Once the stack is in the injector open position it does not need to have a continuous supply voltage and will remain in the open state until the close command. For this reason never disconnect the injector multi-plug with the engine running. If the injector is in the open state it could hydraulic lock the engine with diesel fuel.
The engine will cut out if the control module detects any faults with the injectors or driver circuit.
Selection of component-related Diagnostic Trouble Codes (DTCs):
U0105 Lost Communication With Fuel Injector Control Module
U0306 Software Incompatibility with Fuel Injector Control Module
U0406 Invalid Data Received From Fuel Injector Control Module
P0200 - Injector Control Circuit
P0201 - Injector 1 Control Circuit
P0202 - Injector 2 Control Circuit
P0203 - Injector 3 Control Circuit
P0204 - Injector 4 Control Circuit
P0205 - Injector 5 Control Circuit
P0206 - Injector 6 Control Circuit
P0207 - Injector 7 Control Circuit
P0208 - Injector 8 Control Circuit
P0209 - Injector 9 Control Circuit
P0210 - Injector 10 Control Circuit
P0211 - Injector 11 Control Circuit
P0212 - Injector 12 Control Circuit
P0261 - Cylinder 1 Injector Circuit Low
P0262 - Cylinder 1 Injector Circuit High
P0264 - Cylinder 2 Injector Circuit Low
P0265 - Cylinder 2 Injector Circuit High
P0267 - Cylinder 3 Injector Circuit Low
P0268 - Cylinder 3 Injector Circuit High
P0270 - Cylinder 4 Injector Circuit Low
P0271 - Cylinder 4 Injector Circuit High
P0273 - Cylinder 5 Injector Circuit Low
P0274 - Cylinder 5 Injector Circuit High
P0276 - Cylinder 6 Injector Circuit Low
P0277 - Cylinder 6 Injector Circuit High
P0279 - Cylinder 7 Injector Circuit Low
P0280 - Cylinder 7 Injector Circuit High
P0282 - Cylinder 8 Injector Circuit Low
P0283 - Cylinder 8 Injector Circuit High
P0285 - Cylinder 9 Injector Circuit Low
P0286 - Cylinder 9 Injector Circuit High
P0288 - Cylinder 10 Injector Circuit Low
P0289 - Cylinder 10 Injector Circuit High
P0291 - Cylinder 11 Injector Circuit Low
P0292 - Cylinder 11 Injector Circuit High
P0294 - Cylinder 12 Injector Circuit Low
P0295 - Cylinder 12 Injector Circuit High
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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