Flashing 4Lo and service engine light on code P0014

Tiny
CREATIQUE
  • MEMBER
  • 2011 LEXUS GX 460
  • V8
  • 4WD
  • AUTOMATIC
  • 163,000 MILES
Flashing 4lo and solid service engine light came on a few days ago when the temperatures dropped. Car seemed to be running fine at the time, no noises, shaking, etc. However was also showing engine oil pressure low when starting and then would go away when the car warmed up. Codes P0014 and P0022. We replaced both sets of camshaft sensors. The next morning car hard trouble starting and same engine oil pressure plus light and digging noise when driving. Had battery tested and replaced, changed oil, filter and air filter. Reset codes.
Drove approximately 400 miles the next day, no issues. Then the following morning, 4lo flashing and service engine light solid were back. Now codes show P0014. We are told this could be the timing chain and to take it to the dealer. Any other thoughts/suggestions?
Do you
have the same problem?
Yes
No
Monday, January 27th, 2020 AT 10:47 AM

3 Replies

Tiny
KASEKENNY1
  • EXPERT
I suspect the issue is related but it is odd that the 4LO is flashing when the variable valve timing is acting up. However, the fact that this P0014 keeps coming back clearly needs to be addressed. I attached the testing that we need to run through but the most common cause is the variable valve timing sensor or the oil control valve.

Specifically the exhaust camshaft. This could be caused by the timing chain jumping a tooth however, this is less likely. I suspect they told you to seek a second opinion because they don't fully understand this system.

The most common cause is a restriction in the oil control valve filter. This could also explain the low pressure oil light coming on.

A lot of times when there is debris (like metal) floating through the system, it gets stuck in the oil control valve screen which can cause intermittent issues.
Was this
answer
helpful?
Yes
No
+1
Monday, January 27th, 2020 AT 6:27 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
It is possible that it is related to timing, however, because you are having an oil pressure issue, chances are it is related to the oil control valve for variable valve timing. The control valve controls timing based on oil pressure.

What needs done is the control valve / VVT actuator needs checked. Here are general directions for testing. However, it does require a scanner to actuate the components.

___________________________

2011 Lexus Truck GX 460 V8-4.6L (1UR-FE)
On-Vehicle Inspection
Vehicle Powertrain Management Computers and Control Systems Variable Valve Timing Actuator Testing and Inspection Component Tests and General Diagnostics Camshaft Oil Control Valve On-Vehicle Inspection
ON-VEHICLE INSPECTION
1UR-FE ENGINE CONTROL: CAMSHAFT OIL CONTROL VALVE: ON-VEHICLE INSPECTION

1. INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY

(a)Connect the Techstream to the DLC3.

(b)Start the engine and turn the Techstream on.

(c)Warm up the engine.

(d)Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Linear (Bank 1), Control the VVT Linear (Bank 2), Control the VVT System (Bank 1), Control the VVT System (Bank 2), Control the VVT Exhaust Linear (Bank 1) or Control the VVT Exhaust Linear (Bank 2).

(e)Check the engine speed while operating the Oil Control Valve (OCV) using the Techstream.

OK:

See Pic 1

If the result is not as specified, check the oil control valve, wiring and camshaft timing gear.

HINT
* Control the VVT Linear (Bank 1): Command to activate the exhaust and intake side oil control valves of bank 1 (Control range: Between -128 and 127%).
* Control the VVT Linear (Bank 2): Command to activate the exhaust and intake side oil control valves of bank 2 (Control range: Between -128 and 127%).
* Control VVT System (Bank 1): Command to activate the oil control valve of bank 1 (Control range: ON/OFF).
* Control VVT System (Bank 2): Command to activate the oil control valve of bank 2 (Control range: ON/OFF).
* Control the VVT Exhaust Linear (Bank 1): Command to activate the exhaust side oil control valve of bank 1 (Control range: Between -128 and 127%).
* Control the VVT Exhaust Linear (Bank 2): Command to activate the exhaust side oil control valve of bank 2 (Control range: Between -128 and 127%)

__________________________________

If you are not familiar with the technical jargon above, chances are it looks like a foreign language. Please let me know if you have questions. However, based on your description, it sounds like it is oil pressure related.

Let me know.
Joe
Was this
answer
helpful?
Yes
No
Monday, January 27th, 2020 AT 6:37 PM
Tiny
JIS001
  • EXPERT
Just to jump in, the engineers at Lexus for some reason thought it would be a good idea to trigger the 4LO light on when the check engine light comes on. So addressing the check engine light will also resolve the 4LO light coming on.

Now you stated earlier that a shop replaced the cam sensors? If that is the case then they replaced the wrong part for the fault codes posted. The issue looks more like the oil control valves are going bad. First thing to check is your oil level. If you have low oil level it will trigger these codes.

Second, are you doing your oil changes at there recommended interval change and are you using the correct oil 0W20. If you do then I would suspect bad oil control valves. P0014 Bank1 sensor "B" would be the oil control valve on driver side on the exhaust side. See first image.

P022 is bank2 sensor "A" which is on the passenger side intake side. See second image. If replacing oil control valves you still have a problem then you would need to remove the valve covers and set the timing up to make sure all timing marks line up properly. If not then the chain needs to be removed to set the timing up properly but that is so rare. But it is possible.
Was this
answer
helpful?
Yes
No
Monday, January 27th, 2020 AT 10:20 PM

Please login or register to post a reply.

Sponsored links