Hello!
BLUF: after cleaning engine the engine runs very rough and I get a P2105-00(2a) throttle actuator control system-forced engine shutdown code."

I have a bit of an embarrassing situation- and need some guidance-
After a offroading activity, my engine was covered in dried mud so I decided to degrease it with degreaser. I sprayed the engine down, let it sit and then washed it off with low-pressure water from the hose. Nothing crazy.
I left the hood open to dry it. A few hours later fired it up and it had a really rough idle and threw the P2105-00(2a) code, cutting power to just the rough idle.
I tried to clear with the GAP tool to no avail.

I am not sure what happened, perhaps a short/water in the ignition coils?
The car was running fine (save for the Engine lean code that has been present for 1.5 years)
Has this occurred to anyone? particularly after rinsing the engine?
Thanks!
James

 

I'd start by blowing out and inspecting the throttle body to harness connection first if I were you. Also make sure that no water got behind the battery or into the fuse box.

In the future, you can minimize the risk of this sort of thing happening after cleaning/rinsing the engine bay by blowing out all the excess water after your rinse, and then as soon as possible running the engine to operating temp to evaporate any remaining water. Wrapping and/or avoiding any electrical connections helps too - and definitely stay far away from the battery box and the very water-vulnerable computers behind it.

EDIT: I haven't looked up the code set criteria for this code in the LR3 btw. But in many vehicles it is set by the ecu because it's getting info from other components that there is an engine problem and then limits power or shuts down as a result. In other words, this code doesnt always mean the throttle body is the problem.
So, let us know year and which engine you have if blowing out/drying the throttle body electrical connector doesnt help....

 

Will do-
and sorry for the lack of truck info- it is a 2007 4.4 with 122k miles. I have had issues with it running to Lean for about a year and a half I could not figure it out and had already spent a lot of money chasing that ghost. In the initial ignition/start of the engine, and whilst running I was checking the Mv of the sensor and noticed that the O2 output voltage was 0.0 on both banks. They are a year old so I wonder if that has anything to do with it.
In the interim, I will check the throttle body and harness.
Thanks!

 

//Update//
So to test the throttle body I switched with my 07 RRS (65k miles) and no dice still the error-
I ran the codes from the GAP tool and got

• P0131-1A (AA) Universal heated exhaust gas oxygen sensor - circuit low voltage (bank 1, sensor 1) - General electrical failure - circuit resistance below threshold
  - Test Failed This Monitoring Cycle
  - Confirmed
  - Test Failed Since Last Clear
• P0151-1A (AA) Universal heated exhaust gas oxygen sensor - circuit low voltage (bank 2, sensor 1) - General electrical failure - circuit resistance below threshold
  - Test Failed This Monitoring Cycle
  - Confirmed
  - Test Failed Since Last Clear
• P2105-00 (2A) Throttle actuator control system - forced engine shutdown
  - Test Failed This Monitoring Cycle
  - Confirmed
  - Test Failed Since Last Clear
• P060E-62 (E8) Internal control module throttle position performance - Algorithm based failure - signal compare failure
  - Confirmed
  - Test Failed Since Last Clear
  - Test Not Completed This Monitoring Cycle
• P0121-00 (E8) Throttle/pedal position sensor A - circuit range/performance
  - Confirmed
  - Test Failed Since Last Clear
  - Test Not Completed This Monitoring Cycle
  

The more I think about it the more I am inclined to believe that water got into the ECU/wiring harness and/or fuse box. I got Mv readings from all sensors so I am not sure what it is?
Can an ECU be "dried out" or something?
Thanks,
James