Hi Paul,
could you clarify the position reference the failure & testing of the Bosch PD injectors, I was under the delusion the Bosch PD injectors were of the solenoid type, (EDC 16) & the Siemens injectors Piezo(Simos PPD 1).
Could you confirm if this isn't the case?


If it is the case that the PD injectors from Bosch are solenoid & from Siemens are Piezo, then the readings would be quite different using the test above.

I have replaced a few Bosch PD & Siemens units, but all the Bosch ones thus far have been solenoid (EDC 16)type. All the Siemens have been PPD 1 Piezo type.

From my experience,when the Bosch solenoid units fail - the engine misfires & continues to run. When the Siemens units fail - the engine cuts out dead.
The Siemens system has been subject to a safety investigation from VOSA, which is why VAG have jumped, initially by reducing the cost of the Siemens unit injector by £300 & replacing them under goodwill for any that failed. Followed by the active recall campaign currently running on vehicles fitted with the Siemens system, (presumably on a safety basis?)70,000 vehicles affected.
Common DTC's for the Siemens failure below;

17448 P1040 - Supply fuel injector(s) A, electrical malfunction in circuit
18578 P2146 - Supply Voltage for Fuel Injector Group A, Open Circuit
18579 P2147 - Supply Voltage for Fuel Injector Group A, Short to Ground
18580 P2148 - Supply Voltage for Fuel Injector Group A, Short to B+
17447 P1039 - Supply fuel injector(s) A, shorted

The Bosch unit injector is still the same price at around £450 + VAT & is not subject to the recall. The Bosch units usually seem good for well over 100,000 miles, the Siemens ones for about 60,000?. Head Harnesses fail on both.

Can anyone else chip in with more to add on this? My post was based on what I have seen in our workshop - which is a small 4 bay affair.

I haven't yet experienced a Bosch PD piezo injector & was wondering which engine this is fitted in & whether it faults the same as the Siemens unit??