Any recommendations as to how to approach a P1111 code/Intake air temperature IAT Sensor circuit intermittent high voltage? And/What's the function of this circuit? What's the location of IAT sensor if there is one?

ER.

 

IAT is the intake air temperature. The sensor measures the temperature of the air right after the air box. It should be available over OBDII. It is packaged with the air flow meter (both sensors are packaged as one part). It is downstream of the air box, right next to it. 2 screws and a connector. One minute to get in or out.

 

Talk about a fast reply, man!

This air box? located under the plenum/behind firewall? Is this sensor located behind the air filter? And/Or is the sensor location positioned else where, and if so, where? Do you know the part number for replacement and where to acquire it?

Appreciate your quick response...

ER.

 

I am a little confused as you will see from the attachment P1111 is what everyone has their fingers crossed for everytime they plug in an OBD scanner.
But in answering your question, the tech manual says the IAT is a part of the MAF.

Intake Air Temperature
The intake air temperature sensor is located in the air flow meter assembly and outputs an analogue voltage to the ECM.
The ECM will substitute a default value equal to 50°C should this sensor fail.

 

Here's another version of the P1111 code:

According to another chart, P1111 is not a air intake temperature sensor problem. It shows "P1111 - Intake Valve Timing Control Solenoid Valve Circuit Bank 1" -- Since the Intake valve timing control solenoid valve uses oil flow to control timing, dirty oil can cause the valve to stuck open or close. Before replacing the valve, change engine oil and filter and reset engine code.

 

This is the big air box that contains the main engine air filter. Should be towards the front, on the right hand side fender. Can't miss it. Other way to describe it is at the end of the big air intake tube.

 

I just read this:

P1111 is not a fault code. It is a special designator Jaguar uses meaning system ready, drive cycles completed after the last fault event. P1000, on the other hand, means system not ready, or drive cycles not completed after the last recorded fault event.

Some OBD II Basics - All P0xxx codes are generic and uniform across all manufacturers and mean the same on every car. All P1xxx codes are manufacturer specific codes. You cannot use a generic code chart to analyze P1xxx codes for a Jaguar.

Next time your car displays an engine fault light, try reading the codes then. If you have a CEL illuminated and the only code read is P1000 or P1111, then you probably have a fault that generic code readers cannot see. Could be a chassis code, for example.

One last thing - Neither P1000, nor P1111 can be erased.

Hope this helps you.

Best,

 

The vehicle shows no check engine trouble light (red/amber) that has any commonality to the IAT sensor, so it's a non-issue? Or best too replace the sensors cause it's easy?

ER

 

The IAT is an input to the engine management system. The warmer the air, the less oxygen there is per unit of volume, so the fuel needs to be adjusted.

Can you post the codes for this again?

 

Actually you can clear the P1111 and get P1000.
You will then have to drive the car until all the readiness tests have been satisfactorily completed. You will then be rewarded with P1111.

I wrote a post a while ago about people who drive themselves crazy trying to clear the P1111.

I thought it was funny but it is the quintessential definition of insanity.

bob

 

P1111 does not mean that. You've used something/somewhere with utterly the wrong meaning - never use the same thing/place again.

P1111 is a good status code. Read jag's meanings for all codes - free download.

 

He's not looking at an IAT code. He's looking at a false meaning.

 

The code is P1111, I can erase it and do a drive with the DB2 testor and see result? I just discovered the (lower radiator hose has a hole wearing in it from rubbing with the fan shroud), that is the lower radiator hose correct?

 

Where is this Jag code download located at?

 

AJ27_2001_OBD2.pdf

 

It's an MAF (mass air flow sensor) It is not a IAT sensor. I removed it for cleaning and reinstalled. The sensor bulb was caked with crud, the inside housing and connector was clean. It's said if this crud is occurring best to replace the air filter and it's never a good idea to replace the MAF just because it's easy to replace, other culprits could be the canary your searching for while the problem may have nothing to do with the MAF. Yes, MAF's can go south. Oil change is even recommended before replacing the MAF, but definitely remove it and inspect for cleaning if necessary. I use only a patch of cloth (NO Solvents) Crud came right off along with using a sharp dental tool to clean the bottom holes that had crud also. Even before cleaning the car performed great, after cleaning the MAF it got even better. I'll clear the P1111 code, replace air filter, test drive and retest too see if code reappears.
See link below for yourself what the MAF looks like for my vehicle:

2002 JAGUAR XK8 4.0L V8 Mass Air Flow Sensor | RockAuto

 

P1111 and P1000 do not relate to any device - MAF/IAT or anything - they are status codes. Do not try to erase them!

 

That is the the lower hose. I have read that it can be installed backwards and that causes the rubbing. It looks the same but isn't.

 

Thank you for your input, I ordered the lower hose for me to install. Any pointers on draining the coolant and gettin that new hose in? Just refill coolant back up through the coolant expansion take with the heater on and wait for the bubbles to go away or what?

ER

 

Well, I tried to erase that P1111 code and it didn't let me. I'll heed your advice and not again attempt to erase that code. I cleaned that MAF sensor and replaced the engine air filter, (I just got the car) the air filter was so dirty it looked like a dead fossilized house cat. The bottom of the air filter housing had so much crap in it including plastic cellophane wrappings, leaves, crud... The engine was choked to the hilt of oxygen.

The car now performs like it was reborn...

Cheers,

ER