[silverseal99]

Stock 2011 335d Sport with 67,000 miles. USA model, left-hand drive.

Just completed CBU clean and going about getting I/M monitors to reset and clear spurious codes. Had 67 miles of combined driving on the car with five of nine readiness monitors reset. The engine was idling smoothly except for an intermittent "miss"--maybe once every two minutes or so (Hmm, never did that before. Troubling.). Power and economy would have felt good to anyone not familiar with a 335d but I own two and something felt just a little bit off (just a touch) under spirited acceleration. (Or was it just my imagination? Also Troubling.)

As I pulled out of a parking lot into traffic, the car went into limp mode. I pulled off the road and queried my InCarDoc app: confirmed codes P0273 (Low voltage in injector #5) and P1729 (irregular running of the engine). I also had a transmission code. I was unable to clear the codes with InCarDoc so when I got home, I hooked up my laptop with Rheingold and pulled:
- 004924 DDE: injector, cylinder 5 activation, and
- 004F6F High irregular rotation

Apparently they were hard faults as I could not clear them in ISTA+ either.

Because the car has low miles and had no problems before the CBU clean (which I had already done on my other 335d), I suspected a faulty electrical contact so I set about to recheck electrical connections and to curse myself for not measuring the resistance of all injectors when I had them out of the car for the CBU clean (181 KOhms resistance is specification).

I pulled the acoustic cover, cabin air filter, and associated accoutrement for access to injector 5. I was able to partly release the connector by reaching in from the driver's side with one small screwdriver to release the lock then simultaneously from the passenger side with another screwdriver to gently pry the connector back off of the injector. However, the fuel line and manifold prevented pulling the connector far enough back to provide access to any electrical contacts. I gently pushed the connector back on with a screwdriver from the driver's side until the lock clicked into place. I repeated this partial disconnect/reconnect procedure about five times to ensure I had good electrical contact with the injector within the connector.

What to do? Although I could have pierced the insulation of the wiring leading to injector 5 with pins and gotten a meter reading in that way, I would not have isolated the injector which might have provided an erroneous reading. Furthermore, injector 5 is exposed to significant rainwater runoff and I didn't want to compromise the insulation at that point.

IDEA: After much reading of internet posts and studying of schematics and other information available in ISTA, I decided to open up DDE box, disconnect connector X200061 (thus isolating the circuits) and access the injectors from that terminal.

Pinout:
Injector Pins Measured Resistance
#1 2 -12 182 KOhms
#2 10 - 7 181 KOhms
#3 6 - 8 181 KOhms
#4 9 - 11 181 KOhms
#5 1 - 3 15 KOhms
#6 5 - 4 182 K Ohms

I measured the resistance to each injector three times with three different multimeters. Clearly injector #5 had failed.

NOTE: Don't touch the leads with your fingers while measuring the resistance or you will parallel the injector with your body and get false readings.

So the good news is I didn't have to pull the intake manifold to measure the resistance but the bad news is I'll have to pull the manifold to replace the failed injector.

I have ordered a new injector and will set about pulling the intake manifold while I await its arrival. I will of course code the new injector to the DDE when it is installed. Bummer.

P.S. - I suspect the "high irregular rotation" pertains to the engine (measured differences between the camshaft and crankshaft position sensors) and is due to the failed injector but will inspect the guibo when I get the car back onto a lift.

[335dlci]

Originally Posted by silverseal99

Stock 2011 335d Sport with 67,000 miles. USA model, left-hand drive.

Just completed CBU clean and going about getting I/M monitors to reset and clear spurious codes. Had 67 miles of combined driving on the car with five of nine readiness monitors reset. The engine was idling smoothly except for an intermittent "miss"--maybe once every two minutes or so (Hmm, never did that before. Troubling.). Power and economy would have felt good to anyone not familiar with a 335d but I own two and something felt just a little bit off (just a touch) under spirited acceleration. (Or was it just my imagination? Also Troubling.)

As I pulled out of a parking lot into traffic, the car went into limp mode. I pulled off the road and queried my InCarDoc app: confirmed codes P0273 (Low voltage in injector #5) and P1729 (irregular running of the engine). I also had a transmission code. I was unable to clear the codes with InCarDoc so when I got home, I hooked up my laptop with Rheingold and pulled:
- 004924 DDE: injector, cylinder 5 activation, and
- 004F6F High irregular rotation

Apparently they were hard faults as I could not clear them in ISTA+ either.

Because the car has low miles and had no problems before the CBU clean (which I had already done on my other 335d), I suspected a faulty electrical contact so I set about to recheck electrical connections and to curse myself for not measuring the resistance of all injectors when I had them out of the car for the CBU clean (181 KOhms resistance is specification).

I pulled the acoustic cover, cabin air filter, and associated accoutrement for access to injector 5. I was able to partly release the connector by reaching in from the driver's side with one small screwdriver to release the lock then simultaneously from the passenger side with another screwdriver to gently pry the connector back off of the injector. However, the fuel line and manifold prevented pulling the connector far enough back to provide access to any electrical contacts. I gently pushed the connector back on with a screwdriver from the driver's side until the lock clicked into place. I repeated this partial disconnect/reconnect procedure about five times to ensure I had good electrical contact with the injector within the connector.

What to do? Although I could have pierced the insulation of the wiring leading to injector 5 with pins and gotten a meter reading in that way, I would not have isolated the injector which might have provided an erroneous reading. Furthermore, injector 5 is exposed to significant rainwater runoff and I didn't want to compromise the insulation at that point.

IDEA: After much reading of internet posts and studying of schematics and other information available in ISTA, I decided to open up DDE box, disconnect connector X200061 (thus isolating the circuits) and access the injectors from that terminal.

Pinout:
Injector Pins Measured Resistance
#1 2 -12 182 KOhms
#2 10 - 7 181 KOhms
#3 6 - 8 181 KOhms
#4 9 - 11 181 KOhms
#5 1 - 3 15 KOhms
#6 5 - 4 182 K Ohms

I measured the resistance to each injector three times with three different multimeters. Clearly injector #5 had failed.

NOTE: Don't touch the leads with your fingers while measuring the resistance or you will parallel the injector with your body and get false readings.

So the good news is I didn't have to pull the intake manifold to measure the resistance but the bad news is I'll have to pull the manifold to replace the failed injector.

I have ordered a new injector and will set about pulling the intake manifold while I await its arrival. I will of course code the new injector to the DDE when it is installed. Bummer.

P.S. - I suspect the "high irregular rotation" pertains to the engine (measured differences between the camshaft and crankshaft position sensors) and is due to the failed injector but will inspect the guibo when I get the car back onto a lift.

Pulling the manifold is quite easy.

[silverseal99]

335dlci, thanks for your response. While pulling the manifold is relatively easy, checking injector resistance from connector X200061 inside the DDE box is far easier and takes a fraction of the time. Furthermore, you don't have the risk of losing or damaging the Backup Rings on the intake manifold during the removal/reinstallation process.