Electric Throttle Control Actuator P1121 Petrol

[timjw83]

Hi Guys - I'm getting the below fault code, hoping you can help.

P1121 Electric Throttle Control Actuator

Vehicle: Navara D40 STX, Spanish, 4.0l V6 PETROL, Manual, 4x4

It's an intermittent problem, where if I reset the computer (by disconnecting the battery for a few mins) the truck works fine. Sometimes when I turn off/on it will come back, sometimes it will last a few days before coming back.
When the engine light comes on – it appears to be in ‘limp mode’ not letting me rev AT ALL, so I have to reset or move the vehicle at idle speed.
I’m thinking that because it works fine sometimes, the TCA can’t be completely stuffed.

It has happened in the past and the only consistency is that I’d recently done some deep water crossings each time. In the past after a battery disconnect its disappeared ‘for good’ – or atleast 6 months.
I’ve got a snorkel – and I’ve checked the air box – all nice and dry.
Also, I have removed the Throttle Control Actuator, given it a good clean with the proper spray cleaner, but it hasn’t made much difference.

Any ideas?

Thanks, Tim

 

[JPMC]

Do you have a copy of the workshop manual?
If not there appears that your P1121 code has three posible faults which I have posted below.


A)
Electric throttle control actuator does not function
properly due to the return spring malfunction.

Electric throttle control actuator
B)
Throttle valve opening angle in fail-safe mode is
not in specified range.
C) ECM detect the throttle valve is stuck open.
Detected items Engine operating condition in fail-safe mode

Malfunction A
The ECM controls the electric throttle actuator by regulating the throttle opening around the idle position.
The engine speed will not rise more than 2,000 rpm.

Malfunction B
ECM controls the electric throttle control actuator by regulating the throttle opening to 20 degrees or less.

Malfunction C
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the engine stalls.
The engine can restart in N or P position (A/T), Neutral position (M/T) and engine speed will not exceed
1,000 rpm or more.

 

[timjw83]

Mate - that's great information. Thankyou for taking the time to post that up.
It sounds like my issue is malfunction A, which from what I can tell means I'm up for a replacement throttle body. New $1000 plus, second hand only a few hundred. The good news is that Nissan say they sell barely any throttle bodies, so they are pretty reliable - hence if I buy a second hand unit, it should last ok.

I'll wait a few days just in case someone has had the same issue before I jump in with a replacement part...

 

[timjw83]

An update on this if anyone ever has the same problem.

I ended up replacing the throttle control actuator (part no: 161197s001) with a second hand unit. This (initially) didn’t fix the problem, (it stayed in limp mode) so I drove it up to my local UltraTune (they have the same diagnostics as Nissan do) only for them to advise the same fault code, indicating a faulty throttle actuator.
It turned out the replacement was also stuffed.

The wreckers sent another actuator, which this time I had installed by an auto electrician (just in case). After installing it, they ran through a number of ‘learning’ procedures and it finally fixed the issue.

Although I didn’t end up using them, NizzBits (Garry) was very helpful and I can’t recommend Prahran Auto Service Centre enough.