1bad351

Hello all,

My 2002 E55 recently developed a miss. Started it one morning and running rough. Check engine light on.
Checked codes and found two.
Code 1 of 2 P0201 Injector circuit open cylinder 1.
Code 2 of 2 P0301 Cylinder 1 misfire detected.
Does anyone have a procedure for checking the injector connector for pulses?
or for testing the injector itself?

Tall Giraffe

Star/Xentry has on / off procedures for individual injectors. Carsoft likely as well. Smooth running tests for ignition coils. Inspect coil pack for cracks on back. You can also listen for the clicks of the injector with a mechanics stethoscope tool at Harbor Freight which is useful for other uses. Inspect for leaks around the injector o rings.

Consider having your injectors rebuilt and flow tested as a maintenance item.

If the code is popping it's probably legit. The tests confirm.

1bad351

I did listen with stethescope. I don't think it was ticking, at least not like others. No continuity across injector. I did get 12v on one pin of connector. The other seemed to fluctuate around 3v*(running)
I think maybe its a dead injector , I will try O'Reilys for a rental noid light set to confirm harness function.

Thanks for the tips

Tall Giraffe

Be sure to return that Noid in 48h or it's yours! Orielly got me that way for an item I rented once. Harness is usually good unless you have corrosion somewhere

If injector, you may be a 6074 ending for your year. They are discontinued new but Bosch has a newer one (new) ending 6302 but different color. or you can find some reman 0674 out there.

1bad351

Ok so I finally got a little free time and tried a noid light to check the injector wiring, Plugged in the noid light on injector # 1 harness and started the car. The light started flashing and continued to flash for about 10 to 15 seconds and then stopped flashing. Unplugged and reconnected, no flashing. Turned ignition off and re started, noid light started flashing but then stopped after about 10 to 15 seconds.
Is this normal? Is the engine control module sensing a lower impedance than an injector and shutting off the pulse to that lead of the harness?

bbirdwell

Possibly a failing injector driver in the Motor Electronics (ME). Pull the injector and send/take it for testing, cleaning, calibration. If injector bad, replace. If injector good, verify wires from injector connector to ME. If wires good, seek out a ME shop to replace the injector driver.
FWIW, if it is the injector, consider replacing all eight at one time with a new, calibrated set. After 21 years, age begins taking its toll.

1bad351

Any ideas as to why the noid light flashes initially and then stops?

1bad351

The injector seems to be bad. With a meter open circuit - no continuity.

bbirdwell

Quick test. Swap two injectors. If the misfire moves, it's the injector. If not, wires or ME.

1bad351

Will the P0201 and P0301 codes need to be cleared first or will they self cleafr? Unfortunately my obd II scanner is not very indepth. I have a replacement injector coming Monday or Tuesday. Will try swapping test then.

shico

I want to reach out to you email me on Versace40k@gmail.com . Help me diagnose a c300 2016

bbirdwell

Those particular codes (0201 and 0301) will show as "stored" and the new cylinder misfire will show as "current". If cylinder two, codes would be 0202 and 0302 current codes.
A good scanner is worth its weight in gold...
Edit: if you have a new injector inbound, just install it and see if it clears the misfire. Less work swapping injectors. Swapping injectors is intended to narrow the range of possible failure modes and reduce expenditures.

shico

O no it doesn’t involve the same code it’s a whole new problem on it own . Kindly give me a way of contact let me reach out to you

bbirdwell

Start a new thread and "ping" me with my username preceded by the "@" symbol. No guarantees.

shico

forgive me but I’m new to this site …

Hello everyone I bought this c300 from Copart with the Vin # WDDWF4JB6GR150643

after the car arrived we were able to start it . but now the car doesn’t accelerate . Everything works perfectly but it looses acceleration power . Sometimes it comes on and goes .

I have changed the ECU
I Have changed the fuel pump
I have changed the injectors
I have changed the high fuel pressure sensor
I have even replaced the engine with another engine and I got the same problem so I know it’s not an engine fault .

please what can be the possible solution to this .

bbirdwell

Don't hijack a thread.
Start a new thread.
Purchase and learn to use a STAR/Xentry diagnostics system. Then post questions and stop throwing money and parts at the car.

1bad351

Finally got a bit of free time to install a replacement injector. Problem solved. Thanks to all for the input. Will replace with a matched set of all eight injectors soon.