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Ross, Diagnostic and repair technician
Category: Car
Satisfied Customers: 1183
Experience:  Licensed diagnostic and repair technician
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My fiat doblo 2001 1.9d red engine light comes on and off and

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my fiat doblo 2001 1.9d red engine light comes on and off and engine starts to run fast then engine starts to chug with hesitant running replaced egr valve and air map but still no joy can you help ..thanks
Hi my name is***** am a diagnostic technician and look forward to working with you.Have you had any diagnostic scans carried out yet to point you to EGR/Mass air faults?
Ross and 2 other Car Specialists are ready to help you
Customer: replied 2 years ago.

hi..yes garage came up with these codes p0120 p0510 andp1400 ihave checked these codes p0120 throttle position sensor same as p0510 p1400 seems to be aDPFE sensor but dont know if my model of car has these sensors fiat doblo 1.9d non turbo

The P1400 code would not be the correct code for this vehicle as P1 codes do not exist on this ECU. only P0 EOBD Codes are used. This is usually a mistake caused by the diagnostic system, your model does NOT have a DPF So it would explain this phantom code. Everything here points to the throttle control circuit. It is showing a circuit failure on the throttle position sensor and closed throttle switch so I suspect this is the throttle pedal sensor going faulty or the wiring between the sensor and the ECU.
ECU Faults can also cause this if the fault is within this circuit, so keep it in mind that a faulty ECU is a possibility, but at this stage the van ideally should be put onto a diagnostic system with live data that records data sent from the throttle sensor to the ECU, if there is clearly a problem with the signal, either the wiring or sensor would be the likely suspect.The wiring would be the next step, check the wiring and connector to the throttle peddle sensor, ensure the pins are dry and clean. Also the wiring to the ECU Should be checked.
Customer: replied 2 years ago.

hi...thanks for your quick reply so my throttle position sensor looks to be likely problem... can you tell me where this is located on engine as i look at engine from front of car.. as for the sake of me i cant find it thanks

From memory, the sensor is connected to peddle its self, some vehicles use a mechanical cable to a sensor in the engine bay but i'm fairly certain the sensor is on the peddle on these engines.
Customer: replied 2 years ago.

hi...thanks once again finally a faulty throttle sensor would give out all these symtoms ie: red engine light coming on and off and intermittent running(hesitant) been told to blank off egr valve but as i fitted a new egr dont think i have to what do you think...thanks

No, based on the fault codes there is nothing to suggest any issues with the EGR system so I would not advise blanking this. The engine management light is simply indicating a fault has occurred and a code has been stored, this can be one of hundreds of possible fault codes and based on the codes you have it all points to a problem with the throttle sensor.
Customer: replied 2 years ago.

thanks so i will replace throttle sensor and take it back to garage and get the ecu reset and see

No problem, feel free to reply if you need further assistance, thanks, Ross.
Customer: replied 2 years ago.

hi...Ross sorry for all that but thought you had left the site you have been agreat help at this very moment i have removed the pedal and sensor and got it in my hand looking at the 6 pin sensor cant see anything wrong with it i have ordered a a second hand one from scrap dealers exact same part number is ***** anyway to check this sensor to see if its working ok thanks

Customer: replied 2 years ago.

hi a very good pedal sensor from scrap dealers removed from a doblo2004 and with a 60day guarantee ....fitted it but alas still the red light comes on when engine reaches normal temp...... and more important still hesitant and juddering on a run...would a faulty sensor switch cause this or is it a mechanical fault.....thanks