Hi, just bought a 2002 Polo 9n 1.2. AZQ 3 pot engine. It has an issue where if i try to gently accelerate to maintain a steady speed the engine jumps. Only once it warms up tho. Rough idle too. I have read many forums regarding similar faults but don't know what to check or replace first. Fault codes read.

17851/P1443/005187 - Potentiometer for EGR (G212): Signal too Low

17811/P1403/005123 - EGR System: Regulation Deviation

16490/P0106/000262 - Manifold / Barometric Pressure Sensor (G71) / (F96): Implausible Signal

16685/P0301/000769 - Cylinder 1 Misfire Detected

01314 - Engine Control Module: Check DTC Memory

17925 main relay circuit malfunction.

Any advice would be greatly appreciated. I am confused between map sensors, new egr valve, spark plugs??? I have already replaced ignition coils.

Thanks

Kris

Hi, just bought a 2002 Polo 9n 1.2. AZQ 3 pot engine. It has an issue where if i try to gently accelerate to maintain a steady speed the engine jumps. Only once it warms up tho. Rough idle too. I have read many forums regarding similar faults but don't know what to check or replace first. Fault codes read.

17851/P1443/005187 - Potentiometer for EGR (G212): Signal too Low

17811/P1403/005123 - EGR System: Regulation Deviation

16490/P0106/000262 - Manifold / Barometric Pressure Sensor (G71) / (F96): Implausible Signal

16685/P0301/000769 - Cylinder 1 Misfire Detected

01314 - Engine Control Module: Check DTC Memory

17925 main relay circuit malfunction.

Any advice would be greatly appreciated. I am confused between map sensors, new egr valve, spark plugs??? I have already replaced ignition coils.

Thanks

Here are the fault codes solutions and causes: The first code in your list should be sorted by fixing the EGR

17811/P1403/005123 - EGR System: Regulation Deviation

Possible Causes

* Exhaust Gas Recirculation (EGR) faulty

* Exhaust Gas Recirculation (EGR) Valve (N18) faulty

Possible Solutions

* Check Exhaust Gas Recirculation (EGR)

* Check Exhaust Gas Recirculation (EGR) Valve (N18)

o Perform Output Test

16490/P0106/000262 - Manifold / Barometric Pressure Sensor (G71) / (F96): Implausible Signal

Possible Symptoms

* Erratic Idle

Possible Causes

* Wiring and/or Connections from/to Manifold/Barometric Pressure Sensor (G71)/(F96) faulty

* Leak in Air Intake and/or Exhaust

* Manifold/Barometric Pressure Sensor (G71)/(F96) faulty

* Engine Control Module faulty

Possible Solutions

* Check Engine Control Module Software Version

o See Special Notes for Details

* Check Timing

o See Special Notes for Details

* Check Wiring and/or Connections from/to Manifold/Barometric Pressure Sensor (G71)/(F96)

* Check for Leak in Air Intake and/or Exhaust

* Check/Replace Manifold/Barometric Pressure Sensor (G71)/(F96)

* Check/Replace Engine Controle Module

Special Notes

* On certain smaller Engines we've seen cases where a buggy Engine Control Unit Firmware can cause these fault codes, additionally there are known Problems with the Timing Chain Tensioners which can also result in these fault codes. Please refer to the related TPL/TSB for more instructions.

16685/P0301/000769 - Cylinder 1 Misfire Detected

Possible Causes

* Ignition system

* Fuel injectors

* Fuel pressure

* Running out of fuel

* EVAP canister purge valve

* Evaporative emission system

* Low compression

* Base engine problems

* Controle Module damaged

Special Notes

* This feature search for engine misfire in a specific cylinder. Most of the time the cause for a misfire is a lack of combustion in a cylinder due to absence of spark, poor fuel metering, or poor compression.

01314 - Engine Control Module: Check DTC Memory

Possible Causes

* Fault(s) stored in Engine Control Module

Possible Solutions

* Check Engine Control Module for Fault Codes

Special Notes

* Engine Control Module stored a Code which influences other Control Modules Functionality.

* To clear this Fault Code you will need to correct the Problem in the Engine Control Module first.

17925 main relay circuit malfunction.

You just need to check basic power and earth's.

Kris

Hi, thats great thanks. Does the ECU memory fault point to a faulty ECU?

You have got such a list of faults there, I would think that at least some of them go back a bit in time and may have been sorted, but the fault codes haven't been cleared. I would tend to clear the faults, run the car for a while and then see how many and what codes show up then.

Regards.

Hi, have reset and these are the ones that have come back.

16490/P0106/000262 - Manifold / Barometric Pressure Sensor (G71) / (F96): Implausible Signal

16685/P0301/000769 - Cylinder 1 Misfire Detected

Fuel Trim System Too Rich

17851/P1443/005187 - Potentiometer for EGR (G212): Signal too Low

Thanks for the advice, loads less now.

Kris

it needs a

set of plugs

no1 coil pack

a new egr valve

pressure sensor removing and cleaning will prob need the throttle body doing too

Thats great thanks for the help! Was reading about your polo the other day, it's a beast!

I have already changed all three coils. Hope I haven't bought a duff one! Got a new EGR on the way and new plugs to put in at the same time. Where is the engine pressure sensor? Is cleaning the throttle body difficult? Just a bit of card cleaner?

Kris

pressure sensor is on the side on inlet manifold will need to be removed throttle body is easy just make sure you remove it or it will dirty the pressure sensor carb cleaner is good for both to clean

if it still misfires after you will need to do a compression test valve seats can burn out if its been drove a while with a misfire

Thanks will have to get it done soon then been like this a while.

Thanks for all the help.

First thing i would do with this is sort the miss fire, as the other 2 fault codes are more than likely being caused by this.

Also before you spend any money do a compression check, these engines are notourious for burnt out vave seats, if this comes back ok, migrate the injector to another cylinder and see if the missfire follows, if it does the injector is faulty and needs replacing.

Reet! I fitted new EGR valve and set of plugs today. Sorted! Now i can get on with lowering and wheels and stuff. Anyone lowered 50mm on set of spax springs? Ride any good?