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Mark, Technician
Category: Car
Satisfied Customers: 1504
Experience:  Qualified City & Guilds
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Hi there, I have a very frustrating problem with my 2003 Hyundai

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Hi there,
I have a very frustrating problem with my 2003 Hyundai Matrix 1.6 Gsi Auto.
Whenever I start from cold, after half a mile the EML starts to flash and the engine starts to run roughly. After about another half mile the light goes out and it runs normally.
I have tried leaving the engine running for 5-10 mins before moving off thinking it is a temperature related problem, but it only comes on after in motion.
Having had a diagnostic done and codes PO722 (output speed sensor. No Signal) P1529 Other $11 Manufacturer Controlled and Cylinder 2 misfire.
I replaced the plugs, leads, input & output speed sensors with new OEM.
Everything was fine for a day, then same problem again, only now the vehicle feels as if it is holding back.
The latest code to come up is:
P1529 $11 Manufacturer Controlled & freeze frame:
Fuelsys 1 CL
Fuelsys 2 N/A
Load Pic % 21.6
ETC o c 60
Short 1 % 3.9
Long 1 % 0.8
MAP (CPa) 70
RPM (Min) 1880
VSS (KM/H) 255
As a retired auto mechanic (pre-computer/diagnostic times) this is really starting to bug me.
Any input with this problem would be greatly appreciated

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Hello, my name is XXXXX XXXXX I will try help you with this.


P1529 is for a comminication fault between the engine control unit and the transmission control unit.


P0722 is a fault on the output speed sensor circuit. However, this doesn't always mean the sensor is faulty. It could also be a wiring fault or a faulty transmission control unit.


Because this fault is intermittent, I would be more inclined to think it was a wiring connector fault. Check all the wiring plugs have a good connection. Open the plugs and check for signs of water or corrosion. Also check any earth points. Your thinking it could be temperature related is also a possibility but not with engine temperature but transmission temperature. It won't start getting warm until you are moving.



Mark, Technician
Category: Car
Satisfied Customers: 1504
Experience: Qualified City & Guilds
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