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Matt
Matt, Engineer
Category: Jaguar
Satisfied Customers: 387
Experience:  Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing
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Five years ago, after just buying the car I had to replace a

Customer Question

Five years ago, after just buying the car I had to replace a throttle body unit. It's run great for about 4 years. NOW my engine warning light and a message restricted performance message keeps popping up. Each time the code indicates that it's the air flow sensor. I replaced it twice with a re-manufactured on and it kept happening They had only cost $60 each. I then tried a junk yard one and it happened again. Yesterday I bought one from Jaguar for $290 and a half an hour later the two warnings appeared again. During these occurrences, over a two month period, on two separate occurrences, I was in heavy traffic, and the car started to chock and I just made it over to the break down lane where it stopped. I had to have it towed to my mechanic twice. One time he replaced the fuel pump but the warning lights are still on and the error code states the air flow sensor. Each time the warnings appear it's after the car has been running great for a few days. The error codes are: P0171, P1000, P1637. They indicate the air flow sensor which NOW after replacing about five of them, I think it's something else. Any thoughts, Roger
Submitted: 1 year ago.
Category: Jaguar
Expert:  Chad Farhat replied 1 year ago.

Hi, I' m Chad. Welcome to JustAnswer. I' m reviewing your question now, and I will be post back with your reply ASAP

Expert:  Chad Farhat replied 1 year ago.

The P0171 , is an oxygen sensor bank 1 fault

BUT none of the possible causes is a mass air flow sensor itself , it is a n air leak between the maf sensor and the throttle body yes , but also list a few possibilities , i have sent you the troubleshoot tree for P0171 for your review .

Expert:  Chad Farhat replied 1 year ago.

THE P1637 is a fault that occurs when the cruise control has an issue an the ecm detects it or when the idle speed deteriorates , it will trigger this fault by the ecm ,

the ecm did not receive a message from abs/tccm module and igntion switch has been on for 5 secs and and the ecm can see this module , or the ecm itself is bad the module exist and he thinks it is not there, which will put car in reduce power mode , several issues but none are the mass air flow itself

i also included the troubleshooting description for the p1637

the p1000 is a readiness monitor system not completed, i m assuming will be the oxygen sensor not ready

I like see a snapshot of the fuel trim values for the car if you can hook up a scanner and take a picture of them and send it to me .

please let me know

Thank You ***** ( aka -Customer)

ASE Certified Tech

Expert:  Chad Farhat replied 1 year ago.

1- Check the air boot from mass sensor to tb has no cracks or leaks in it, visually looks thru the ridges , with a flash light .

2- what is the fuel pressure

3- can we get a reading on the oxygen sensor bank1 sensor1 , is switching on the scanner from 0.1 v to 0.9 volts , or is it reporting correctly ?

4- can you get me a live data snapshot of the fuel trims at idle ( the long term fuel trims and the short term fuel trims at idle )

5- I like to know the P1000 not readiness test is for which system , the scanner should indicate that .

please let me know

Thank You ***** ( aka -Customer)

ASE Certified Tech