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Jay
Jay, Certified Infiniti Technician
Category: Infiniti
Satisfied Customers: 18893
Experience:  20+years, Nissan and Infiniti experience and currently now working for a Infiniti Dealer
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2007 FX35 with no start. CKP has been replaced and indicates

Customer Question

2007 FX35 with no start. CKP has been replaced and indicates 200 RPM on scan tool during start condition. Fuel Pump relay engages telling me the CKP pulse was received. All Battery, Ignition, and Grounds to ECM are good. Scan tool communicates with ECM and sometimes shows P2100 and P2101. No spark and no Injector pulse.
JA: How many miles are on the car? Has the car been starting normally?
Customer: Customer says it quit while driving. Take me a minute to see mileage,
JA: Are you fixing your FX35 yourself? What have you tried so far?
Customer: Yes, I have been training for GM for over 25 years and have 36 years in automotive business. Sent the ECM of and had it rebuilt but same problem exists. Also replace CKP sensor with Dealer Sensor and not aftermarket.
JA: Anything else you want the mechanic to know before I connect you?
Customer: No security lights on the cluster.
Submitted: 3 months ago.
Category: Infiniti
Expert:  Jay replied 3 months ago.

Hello my name is ***** ***** thank you for your question.

These codes are not crank sensor related, but throttle chamber or harness issue related.

Let me provide you with the diagnostic steps for these codes .. Hang on please.

Expert:  Jay replied 3 months ago.

https://dl.dropboxusercontent.com/u/105565483/a.pdf

Those are the complete diagnostic steps for these two trouble codes right out of the factory service manual. This is most likely either a throttle chamber issue, or something in the harness. Other wise if not either, then it would be a Ecm.

Do you have any more questions on this?

Customer: replied 3 months ago.
I am aware these are not CKP codes and they are Throttle Chamber Codes. The ECM does not switch on the Throttle Relay on the control Circuit. I can ground it my self and it works fine, but this code does not appear to be a no start condition,,,
Expert:  Jay replied 3 months ago.

If it's harness related, or Ecm related it could certainly affect the vehicle from starting.

Customer: replied 3 months ago.
If it was harness related, why are all the power and grounds good? The CKP is working as well. What about security? Does the ECM disable spark and fuel both?
Expert:  Jay replied 3 months ago.

I know the Cam and Crank sensors are major signals for the Ecm to provide Spark and injector pulse. But if there is a harness issue, it can certainly interrupt the signals from getting to the Ecm. There is allot of factors. That is why I supplied the diagnostic steps for you. This way you can follow the steps to isolate the issue.

Expert:  Jay replied 3 months ago.

The Ecm does determine spark and it does determine injector pulse.

Do you want the Ecm terminal reference also?

Customer: replied 3 months ago.
I will look at the diagnostic steps, however I have checked the Left and Right Bank Cam sensors and CKP with an lab scope and patterns are perfect. I already have the wiring schematics.
Expert:  Jay replied 3 months ago.

The IPDM is also some thing that should be checked.

Expert:  Jay replied 3 months ago.

For the codes you are getting, I would not be focusing on the Cam or Crank Sensors. I would be focusing on the codes you are getting. That is the fault the Ecm is detecting and this fault may be feeding back to the Ecm which is putting the Ecm at a point where it won't provide spark or injector pulse cause it has no throttle response.

Does the cooling fans come on when the key is turned to the ON position?

Customer: replied 3 months ago.
My thoughts as well, but if would have to be in the CAN line portion as all relays and fuses supplying power to the Injectors, Coils, ECM, MAF, etc are working as designed,
Customer: replied 3 months ago.
as if it was in fail safe mode,,,,
Expert:  Jay replied 3 months ago.

Oh.. The fans are on?

Customer: replied 3 months ago.
At Times yes,,,
Expert:  Jay replied 3 months ago.

Them being on, is a sign of control unit failure or communication.. That is fail safe. So this is certainly a control unit communication issue

Expert:  Jay replied 3 months ago.

The IPDM is a control unit that I would be inspecting as well as the Ecm. I no longer believe the fault code based on the fans. I would be focusing on a control unti

Customer: replied 3 months ago.
Which Control Unit?
Expert:  Jay replied 3 months ago.

Ecm or IPDM, those are what I would focus on.

Customer: replied 3 months ago.
Just got the ECM back from rebuilder.
Expert:  Jay replied 3 months ago.

The IPDM is a major control unit that can be easily over looked. It is a Computer controlled fuse box that is behind the battery.

Oh jezz... That is one of the first things I don't trust!!! to many times I have been burned by Ecm rebuilders or repairs. If the Ecm had been burnt I would not trust it. I would rather a used on verses a repaired on

Customer: replied 3 months ago.
If the CAN line is down, will the Scan Tool communicate with the ECM?
Expert:  Jay replied 3 months ago.

It may not if the IPDM is the issue. If you can see the IPDM but not the ECM, then you know it's the ECM. If you can't see the IPDM or Ecm, it most likely is the IPDM.

The IPDM more or less powers the Ecm.

Customer: replied 3 months ago.
I fully agree on rebuilders, but I did remove the cover before I sent it and no visual burns or smell. My scan tool does not see the IPDM so it could be the problem.
Expert:  Jay replied 3 months ago.

That is where I would focus on. It's actually cheaper to get one of them used verses a Ecm

Expert:  Jay replied 3 months ago.

examine all the plugs and connectors. Look for corrosion while you are at it. But I would certainly be looking at the IPDM, especially if you can't see it when doing a CAN system call.

Expert:  Jay replied 3 months ago.

Do you have any more questions on this?

Customer: replied 3 months ago.
I noticed in the schematic that The IPDM had the CAN lines connected as part of the starting system. I always check corrosion and terminal tension as GM is the world worse for those problems. Do you know if the Snap On scan tool will communicate with the IPDM?
Expert:  Jay replied 3 months ago.

I am not familiar with the Snap on scanner enough to say. I am use to using the Nissan/Infiniti scanner when doing CAN system diagnostics.

Customer: replied 3 months ago.
OK its getting late and I will check communication with the IPDM in the AM,,,,, Thanks
Expert:  Jay replied 3 months ago.

Your welcome and thank you for using JustAnswer.com

Don't forget to Rate me if your Satisfied with my help. I hope I have provided you with Excellent Service

Thanks Jay!

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