I was driving on the freeway friday night and I notice the SES light pop up (I wasnt boosting or driving hard, just cruising). I pulled over and checked the code with my OBD II reader and it said P0172 "Bank 1 too rich" I cleared code and noticed my AFRs on my guage running about 12.5 at idle...I was smelling gas. I drove home and cruising AFRs were about 13.2. I get ONE block away from my home and the car just shuts off. Cranks wont start. I had my wife just push the car with hers to a parking spot in front of the house.

So I finally had car towed to the shop that build the turbo. They ran compression test on all 6 cylinders and no problem. Then they found a blown 15A fuse in the long fuse box under the hood that said "ENG CONT 1" They replaced the fuse and car started right up. So they decided to drive car around parking lot and it was fine. The owner of the shop said take it out on the road and make sure. So they were driving down the street and started accelerating a little to keep up with traffic and car shuts off. They open the hood...same blown fuse "ENG CONT 1" they replace it and drive back to shop and try to accelerate to keep up with traffic...blows again...same fuse.

So now they are getting P0222, P1121 and P1122 codes when fuse blows. They are trying to tell me its the Throttle body going bad and I may need to replace it but I dont believe its the TB. That does not account for the P0172 code that I got before it blew the first time. The TB is relatively new off a 2009 Maxima and has been fine up until now. I think it might be some short in the wire or something somewhere in the engine. Anyone else had these problems before? Any advice?

 

Trying to find out what all devices are connected to this "ENG CONT 1" circuit looking at the FSM but perhaps Im not finding it...because if TPS and Fuel on Bank 1 are all on this circuit that would tell me that a wire somewhere on this circuit is damaged or rubbing against something or whatever.......

 

Damn man, hope you figure it out, not at all near a Electrial Pro or Amateur ...Good Luck...

 

Just ask them how they narrowed it down to the throttle body. Makes since to me though, if the TB is on that circuit, if it was failing to open properly, the engine would run rich. Not sure why both banks wouldn't read rich though.

Yes, could be a wire. Run over anything recently? I know the eng cont on my 3rd gen feeds the O2 sensors. I ran over something that shredded my O2 wiring and it would randomly short and pop the fuse till I fixed it.

 

Yeah I finally found out what is on that "ENG CONT 1" Its:

O2S1B1 (O2 secondary bank 1????)

02H1B1 (O2 ??????? primary bank 1???)

FUELB1 (something with Fuel Bank 1??)

So I doubt seriously its a TPS. Because TPS is not even on that circuit. I think something wrong with wiring on one of the Bank 1 O2 sensors or some fuel injector issue on Bank 1. Fuel injectors brand new....dont know.

 

upon further research found out injectors not on that circuit either...its only the O2 sensors for bank 1 on that "ENG CONT 1" circuit that keeps blowing.

 

That really narrows it down then! Waiting for final word.

 

Can never remember all the smilies to key them in in the mobile app! - FIXED!

 

If it's fuse #58 from Fusible link box under the hood then it powers IACV among other things that's why shop is leaning towards 'bad TB' since IACV is the only part of TB capable of blowing that fuse.

If I understand diagrams correctly O2 sensors are powered from fuse #8 which is located in the cabin under the dash on the driver side.

 

This is not the ENG CONT 1 fuse.

First you have to translate the name ENG CONT 1 into a fuse number, which is fuse # 58. Then you go to page 10 of the FSM which is called "Power Supply Routing" and look for fuse # 58.

You will see that fuse # 58 powers things called MAIN, PGC/V, IGNSYS, ICVB1 and ICVB2. Nissan calls these names "Cell Codes" which are the names of electrical schmatics. Nissan claims that these names are in the alphabetical index (IDX.PDF) section of the FSM, but I can guarantee you that that not always true. In the case of fuse # 58, the IVCB1 and 2 are not in the index.

For an expanded version of the name, go to page EL-477. There we find that:
MAIN = Main Power Supply and Ground Circuit
PGC/V = EVAP Canister Purge Volume Control Solenoid Valve
IGNSYS = Ignition System
IVCB1 = Intake Valve Timing Control Solenoid, Right Hand Side
IVCB2 = Intake Valve Timing Control Solenoid, Left Hand Side
VIAS/V = Variable Induction Air Control System *

* The last one, VIAS/V, is not listed on page EL-10 but when you look at the MAIN schematic, you will see that a wire from fuse # 58 goes to the VIAS/V schematic. But when you go to the VIAS/V schematic on page EC-701, it shows that the VIAS solenoid is connected to fuse # 20. Hmmm

 

I don't think that you are correct on this. The electrical wiring for fuse # 58 is not the same for all the 5th gen year models. 2000 is unique to itself, 2001 is unique to itself and 2002/2003 are the same. the op has a 2002, so that's the FSM you have to be looking at.

 

I'm not, you're right- I was looking at 2000 diagrams. #58 cannot power IACV as it's simply doesn't exist on 2k2 model . Anyway, TB motor is powered through fuse #63 which is not the one they keep replacing.

O2 sensors are still powered through #8 in this year.

 

You are right.....I was looking at it all wrong. It's fuse #58 on the diagram. Thanks! I hate tracking down electrical problems......

 

OK here is the fuse that keeps blowing...



Fuse Diagram.....from FSM




Am I correct?

 

Yes:

 

Alright...I think I know almost 100% what the problem is now then......thanks!

 

FOUND PROBLEM.......

Found short. This is the chargepipe coming from the compressor on the turbo. This is a view of from top of engine on drivers side. The pipe is connected to a 90 degree silicone connector and from there goes down past radiator under the front of the car into the intercooler. There is a refrigeration sensor there. Once I boost the pipe is being pushed forward and hit the positive wire on the sensor grounding it out causing blown fuses and limp mode in ECU, Terrible erratic AFRs, and 18 codes. I loosened the tclamp pulled pipe further into the intercooler and tightened tclamp back. Going to take the car back to shop that build turbo on Tuesday and they are going to weld a lip on to the chargepipe so that when I tighten the tclamp and boost the chargepipe doesnt move forward anymore. PROBLEM FIXED!! NO MORE CODES, BLOWN FUSES, ECU out of limp mode AND RUNS PERFECT NOW.....AFRS PERFECT!!

BEFORE......



After....

 

Amazing troubleshooting the more i read the more i learn on how to go about a problem, thanks for sharing