Training on the job

Maurice Business Development Manager Geebung, Australia Posted   Latest   Edited  
Case Study
Driveability
P0205 - Cylinder 5 Injector "A" Circuit

Ford Territory 2008 Vin 6FPAAAJGAT8E91797

Some days I feel I am losing my diagnostic ability or maybe my sharpness to diagnose, but then I have a run of success and I realise I am not as bad as I think I am. 

Am I the only one to feel like this?

Well I felt pretty good today I had Karan my up and coming tech who is not long out of his time come into me this morning after diagnosing a Ford Territory misfire. Before he started I pre-empted by suggesting to Keran I bet this will be a coil.

Well some 30 minutes later Karen came in to tell me he tested the coil on cyl 5 the cylinder that was not firing and found it to be ok. I asked him what code was found and he told me the car had a P0205 (Inj 5) well I said why did you test the coil, and he said you told me you thought it would be a coil so I went straight for coil.

Well I deserved that one so I educated Keran, scan tool direction always takes precedents over anything we think. The fact that the DTC points to the injector means you do not need to check the ignition coil. I explained that he just wasted 30 minutes and cost the customer and extra half hour in labour chargers. I do this to teach him to think and to learn not to make him feel bad.

Anyhow I decided to come out and help give him some direction. I got him to hook up the pico to cylinder 5 injector. We had a flat 12v on both sides of the injector with the car running. I then suggested he try another injector just to verify we were hooked up correctly which of cause we were.

So I asked him why you think we have 12V and it is not pulling to ground and driving the injector. He said because we have a cam or crank sensor problem. I said then why is it working on the other 5 cylinder. Sure there could be a very slight chance we have a relactor wheel issue on one of the pickups, but this is not where we need to go just yet.

You need to verify your wiring to the PCM and after that yes we can check and verify the cam and crank signal and if all this proves ok then I would expect we have an injector driver issue.

Well I went back into my office while Keran unbolted the PCM and exposed the wiring terminals. He hooked up the scope to A8 terminal which was the injector 5 driver terminal and he had 0V. I came out and asked him what is this telling us? I reminded him how when he was an apprentice I taught him how to understand voltages and how to use voltages to diagnose open and short circuits.

It was obvious we had an open wire, and we had narrowed our issue down to the no 5 injector wire that ran between the injector and the PCM. No amount of wriggling would turn on our injector, so I showed Keran how to verify my theory was 100% correct.

I simply left my back probe in the terminal of the PCM and added a second back probe to the injector driver terminal of the injector and I simply joined a wire between each back probe and simply stared up the engine and bingo the car was running on all six cylinder once more.

The open wire was not easily found and due to time restraints it was more economical to run a new wire along the outside of the engine loom to the injector. With it all taped up it was hard to tell it was even there.

The customer was happy and Karan who is one year out of his time is learning something new every day. It is important to keep your staff learning and interested in their jobs, a happy staff means he or she is less likely to want to leave with in the near future.

+4
John Instructor
Beaver, Pennsylvania
John
 

"Before he started I pre-empted by suggesting to Keran I bet this will be a coil. Well some 30 minutes later Karen came in to tell me he tested the coil on cyl 5 the cylinder that was not firing and found it to be ok. I asked him what code was found and he told me the car had a P0205 (Inj 5) well I said why did you test the coil, and he said you told me you thought it would be a coil so I went

+4 Ð Bounty Awarded
Maurice Business Development Manager
Geebung, Australia
Maurice
   

Thanks John, love your comments, I defiantly should not have suggested a coil without any diagnostic reason and I am certainly at fault and will not do this again, but at the time my intent was more to explain the type of miss being like that of a coil breaking down. It is so hard sometimes when talking with staff not to use examples such as the case here. I never encourage any of my staff to

+1 Ð Bounty Awarded
Steven Mechanic
Spokane, Washington
Steven
 

Hello Maurice, I think this was a learning experience for both of you guys, and everyone else. Don't play the guessing game, its bad for everyone.

0 Ð Bounty Awarded
Maurice Business Development Manager
Geebung, Australia
Maurice
 

Thanks Steve, no I never play the guessing game and my intention in thinking we could have had a coil problem was just form experience these 4.0L are notorious for coils breaking down it was never my intention for my staff to go straight for the coil without any diagnostic reason to do so. But yes it was a lesson for me too because there is a lot of power in our words and had I not have

+1 Ð Bounty Awarded