P0850 - Fault with clutch position sensor (N/P safety switch).
P0507 - Caused most likely by above fault.
U0155 - Fault with communtications error with the guage cluster.
Both seem to go hand-in-hand:
- http://www.mazdaspeedforums.org/foru...7-codes-98813/
- http://www.mazdas247.com/forum/showt...ting-Desperate
- http://forum.mazda6club.com/engine-d...high-idle.html
Does this description sound right?
After changing the clutch peddle position switch, my car threw the codes for Neutral/Park Safety Switch Circuit Fault (P0850), and Idle RPMS Higher than expected (P0507). The car was having some bubble idle, and when I'm stopped if I let out the clutch and have the brakes pressed down, the RPMs will rise to about 1300, and at times rise up to 1500 RPMs, drop back down to 1000, then rise and then drop, etc. I had also noticed that when I brake from higher acceleration the RPMs drop to near stall, though never stall, then rise back up to idle.
Some people change the sensor, others just reset the ECU. Might be worth doing the reset to see if that clear it before forking out for the sensor. When you reset it shoudl idle normally, when you press the clutch then release it should stay stable, if it throws those codes again then chances are it is the faulty sensor.
Last edited by DAN MPS 3; 03-03-2014 at 02:47 PM.
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