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Richard, Jaguar Technician
Category: Jaguar
Satisfied Customers: 15511
Experience:  12 years at a Ford/Lincoln Mercury and Jaguar dealer as technician and shop foreman.
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We have a 2009 Jag XF coming in with a P050B code again

Customer Question

We have a 2009 Jag XF coming in with a P050B code again after we did the thermostat last time and reset the code. Any ideas what it could be? The car starts slowly after sitting which we thought would be the fuel ck valve not holding pressure in the fuel line. Thanks, Tony
Submitted: 1 year ago.
Category: Jaguar
Expert:  Richard replied 1 year ago.

First we should check the battery as low voltage on start up can be the cause. Next that extended crank can be the cause if we have a failing pump. Usually that code is accompanied with others like cylinder misfire codes. If not then we may have to have the ECM reprogrammed by Jag. Let me know.

Customer: replied 1 year ago.

scanned the car this morning, found p050b but no low battery indications. freeze frame showed ECT 61F, IAT 59F, MAF 1.65 lb/min, STFT1 -14%, LTFT1 3.9%, STFT2 -25%, LTFT2 4.68%. Looks like too rich when cold, possible MAF problem?


Expert:  Richard replied 1 year ago.

Yes does sound like it is running rich. Disconnect the negative battery terminal to reset the fueling adaptions and clear the code.