How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask James Your Own Question
James, Ford Technician
Category: Ford
Satisfied Customers: 3589
Experience:  Ford Senior Master Tech, Ford gas and diesel expert, ASE Certified
Type Your Ford Question Here...
James is online now
A new question is answered every 9 seconds

340 and 344 Codes after replacing both cam shaft sensors,

Customer Question

340 and 344 Codes after replacing both cam shaft sensors
JA: Have you scanned the code? Have you tried to reset it?
Customer: yes and yes
JA: What is the model/year of your Ford?
Customer: 05 Expedition
JA: What year is your Ford?
Customer: 05
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: I already told already
JA: Sorry about that. I must have missed it. Could you tell me again?
Customer: I replaced both cam shaft sensors. Yes hoping to fix this myself
JA: Anything else you think the mechanic should know?
Customer: Vehicle seems to be running fine since replacing both sensors but still throws the codes
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Ford Mechanic about your situation and then connect you two.
Submitted: 5 months ago.
Category: Ford
Expert:  James replied 5 months ago.

Hello, does the vehicle idle rough when the engine is hot?

Customer: replied 5 months ago.
Just a little around 550 rpm
Customer: replied 5 months ago.
All in all runs pretty smooth but the check engine light stays on all the time throwing the 340 and 344 codes. Before I changed the sensors, it threw the codes for both banks, but now only one
Customer: replied 5 months ago.
Throwing bank 1 code. Is that passanger side?
Expert:  James replied 5 months ago.

bank 1 is the passenger side. If the sensor didn't correct it the issue is likely the pigtail connector causing the issue.

Customer: replied 5 months ago.
I read something about it could be the alternator. Something about a diode or something. Have you heard anything like that?
Expert:  James replied 5 months ago.

Yes there is an alternator ripple test that can interfere with the camshaft sensor signal. To Diagnose you need an engine scope to monitor the ripple. I have only ran into that issue once. I don't think that is as common as the pigtail failing. Also the pigtail is a little less than 20 to repair instead of a 300 alternator.

Related Ford Questions