# 2009 Altima no power and won't go into gear.



## KristinF (Mar 29, 2021)

Hi all, 
I just got a 2009 Altima (with 190,000 miles on it) about a month ago and it ran well until a few days ago. It used to belong to my niece, and I'm pretty sure it had never broken down on her before. I was on the freeway and went to press on the accelerator pedal to pass a truck and it was as if I had put the car into neutral, and when I pressed on the accelerator pedal it wouldn't rev up. It had zero power so all I could do was coast to the shoulder of the freeway and have it towed home. In researching what could be wrong I have heard the term 'limp mode' or 'fail safe' mode. I'm wondering if this could be it and what would cause it. I ordered a BlueDriver Bluetooth Pro OBDII Scan Tool for iPhone off of Amazon thinking that this might help me to diagnose the problem. Does this sound familiar to anyone? Can anyone offer any info that can help me to diagnose the problem? 
Thank you in advance, Kris


----------



## rogoman (Dec 16, 2004)

*Fail-safe* terminology refers to a device or system that is designed to keep the vehicle operating safely in the event of a failure. A fail-safe isn't designed to prevent failure but mitigates failure when it does occur. A prime example is a MAF failure which will put the engine system into fail-safe resulting in reduced performance like preventing operation beyond 3000 rpm. In your case, the vehicle did not go into fail-safe and continued to operate; instead you had dead failure.

The "BlueDriver Bluetooth Pro OBDII Scan Tool for iPhone" looks like a nice advanced OBD scan tool. Perform the ECU code readout with your scan tool to see if any fault codes are set. Post the actual codes here on the forum so that we may be able to help you further. If there is one or more fault codes set, they can help point to the malfunction.

A common problem with random engine shutdowns is a marginal camshaft position sensor or a marginal crankshaft position sensor. Most of the time when this happens, the "check engine light" never comes on; subsequently when performing an ECU code readout, there was no fault code set. There's been many members here on the forum that have had problems similar to yours and the fix was replacing those two sensors.

The best and cheapest fix for this situation is to replace both sensors at the same time; the reason for doing this is there is no way to determine which sensor is at fault with this type of condition. You can take your vehicle to a dealer/repair shop and they'll tell you there is nothing wrong after they go through with diagnostic tests because at that time the vehicle was running OK. You could end up spending $200 or much more depending on how much time/parts are used.

When replacing sensors, always use Nissan OEM parts from a Nissan dealer; aftermarket electronic items generally are not reliable, don't last long, and many times are DOA. The sensors are not very expensive; around $75.


----------



## KristinF (Mar 29, 2021)

rogoman said:


> *Fail-safe* terminology refers to a device or system that is designed to keep the vehicle operating safely in the event of a failure. A fail-safe isn't designed to prevent failure but mitigates failure when it does occur. A prime example is a MAF failure which will put the engine system into fail-safe resulting in reduced performance like preventing operation beyond 3000 rpm. In your case, the vehicle did not go into fail-safe and continued to operate; instead you had dead failure.
> 
> The "BlueDriver Bluetooth Pro OBDII Scan Tool for iPhone" looks like a nice advanced OBD scan tool. Perform the ECU code readout with your scan tool to see if any fault codes are set. Post the actual codes here on the forum so that we may be able to help you further. If there is one or more fault codes set, they can help point to the malfunction.
> 
> ...


I cannot thank you enough for your reply. Knowledge is priceless - thank you for sharing it with me. The scanner should arrive tomorrow by 10pm so I probably will be able to use it on Wednesday. I will post the results here. Thank you again!


----------



## KristinF (Mar 29, 2021)

rogoman said:


> *Fail-safe* terminology refers to a device or system that is designed to keep the vehicle operating safely in the event of a failure. A fail-safe isn't designed to prevent failure but mitigates failure when it does occur. A prime example is a MAF failure which will put the engine system into fail-safe resulting in reduced performance like preventing operation beyond 3000 rpm. In your case, the vehicle did not go into fail-safe and continued to operate; instead you had dead failure.
> 
> The "BlueDriver Bluetooth Pro OBDII Scan Tool for iPhone" looks like a nice advanced OBD scan tool. Perform the ECU code readout with your scan tool to see if any fault codes are set. Post the actual codes here on the forum so that we may be able to help you further. If there is one or more fault codes set, they can help point to the malfunction.
> 
> ...


----------



## KristinF (Mar 29, 2021)

I just got the scanner and here are the results... 

*2009 Nissan Altima L4, 2.5L 

P0720 *The Rpm Sensor 'Output Shaft' Has An Electrical Fault 

*B2109- *Steering lock relay off: No Sub Type Information *00 *
CONFIRMED 

*P0725 *Engine Speed Input Circuit HISTORY /
CURRENT

*P0720 *The Rpm Sensor 'Output Shaft' Has An Electrical Fault HISTORY /
CURRENT

*P0746 *Pressure Control Solenoid "A" Performance/Stuck Off HISTORY /
CURRENT

*P0826 *M-Mode Switch HISTORY /
CURRENT

*P1701 *Transmission Control Module (TCM) power supply HISTORY /
CURRENT

Thank you again for any help in understanding this.


----------



## VStar650CL (Nov 12, 2020)

"Limp mode" for the CVT will make the car seem like it's starting out in a higher gear, the TCM locks the belt and pulleys at a "middle" ratio. It won't prevent the car from moving. If you get zero movement in either direction and the fluid is okay, chances are the tranny is trashed.


----------



## rogoman (Dec 16, 2004)

KristinF said:


> I just got the scanner and here are the results...
> 
> *2009 Nissan Altima L4, 2.5L
> 
> ...


You've got a multitude of codes, some related, some not. There may be a problem with the charging system. A properly working charging system puts out about 13.2 to 15.0 volts, A battery should have a static charge of 12.2-12.6 volts. If a battery is not good, the charging system may not be able to charge properly. When a charging system is not charging, or overcharging, a lot of "strange" things can occur. It's not uncommon to see a multiple of stored trouble codes in the ECM memory. So, whenever a car is setting a multiple of trouble codes, idling funny or stalling, or anything out of the "norm," test the charging system before you start pulling hairs!


----------



## KristinF (Mar 29, 2021)

VStar650CL said:


> "Limp mode" for the CVT will make the car seem like it's starting out in a higher gear, the TCM locks the belt and pulleys at a "middle" ratio. It won't prevent the car from moving. If you get zero movement in either direction and the fluid is okay, chances are the tranny is trashed.


Thank you. I really don’t know much about transmissions. I'm going to check the starting/charging system first since it will probably be easier for me to test than the trans.


----------



## KristinF (Mar 29, 2021)

rogoman said:


> You've got a multitude of codes, some related, some not. There may be a problem with the charging system. A properly working charging system puts out about 13.2 to 15.0 volts, A battery should have a static charge of 12.2-12.6 volts. If a battery is not good, the charging system may not be able to charge properly. When a charging system is not charging, or overcharging, a lot of "strange" things can occur. It's not uncommon to see a multiple of stored trouble codes in the ECM memory. So, whenever a car is setting a multiple of trouble codes, idling funny or stalling, or anything out of the "norm," test the charging system before you start pulling hairs!


Thank you. What you said makes sense so I think I will start with checking this system first. Not to figure out how to do that. 😊


----------



## smj999smj (Jan 1, 2006)

KristinF said:


> Thank you. What you said makes sense so I think I will start with checking this system first. Not to figure out how to do that. 😊


Do a web search for "Nico Club." They have free, online, Nissan service manuals at their site that can help you with their diagnostics. I wouldn't be surprised if you find out the CVT transmission is bad; they don't have the best history of reliability.


----------

