Help Required, 1.4TDi 70, BNM ballache...

[RjBlack]

So. Bare with as it's kinda lengthy. Bought an '08 Polo with a 1.4TDi from a mate down south, very cheap. Got plenty of MOT, with only one issue, EML & Glow plug lamp illuminated/flashing. Drove it back home to central scotland over night in limp mode, car won't go past 3-3,500rpms, pretty sure mpg is taking a hit too, getting about 450+/- miles a tank currently. Anyways, got home, got it on a generic code reader. P0726 code shown, many folks talking about it being a Crank position sensor. Took me about 3 days to even find a guide to show me where it was, found a haynes manual, found the sensor. I unplugged it and tried starting the car, car cranked but obviously didn't start.

Would I be correct in saying that if it were the sensor throwing up the error, that it wouldn't matter if it were plugged in or not, and the car wouldn't start at all?

What would be some other culprits?

If I'm taking this to a garage, what can I expect to fork out for the fix?

Just to note, I've little tools got a rachet, spanners etc., no voltmeter or anything such as that. Not alot of money either so cheapest fix possible would be great (lol cheap and cars don't go, I know) I've little knowledge with these engines, but willing to give things a go as long as I don't feel it's too far out my comfort zone.

Thanks in advance

 

[BobnOH]

VAG Error Code: 17110/10657
EOBD II Error Code: P0726

Fault Location:
Engine Speed Input Circuit from Engine Control Module (ECM) - Range/Performance Problem/Upper Limit Exceeded/Implausible Signal

Possible Cause:
Malfunction Indicator Lamp (MIL)(K83) active.

Wiring/Connector(s).
Crankshaft Position (CKP) Sensor.
Communication error between the Engine Control Module (ECM) and Transmission Control Module (TCM) (J217).

When is the code detected?:
The P0726 Codes is triggered when the Transmission Control Module (TCM) detected that the calculated engine speed is greater than the RPM's received from Engine Control Module (ECM).

Description:
The Engine Control Module (ECM) monitors the engine speed through the Crankshaft Position (CKP) sensor with the engine running, and send signal to the Transmission Control Module (TCM).

 

[RjBlack]

VAG Error Code: 17110/10657
EOBD II Error Code: P0726

Fault Location:
Engine Speed Input Circuit from Engine Control Module (ECM) - Range/Performance Problem/Upper Limit Exceeded/Implausible Signal

Possible Cause:
Malfunction Indicator Lamp (MIL)(K83) active.

Wiring/Connector(s).
Crankshaft Position (CKP) Sensor.
Communication error between the Engine Control Module (ECM) and Transmission Control Module (TCM) (J217).

When is the code detected?:
The P0726 Codes is triggered when the Transmission Control Module (TCM) detected that the calculated engine speed is greater than the RPM's received from Engine Control Module (ECM).

Description:
The Engine Control Module (ECM) monitors the engine speed through the Crankshaft Position (CKP) sensor with the engine running, and send signal to the Transmission Control Module (TCM).

Isn't the TCM only in automatics? Mines is a Manual 5 speed

 

[STDOUBT]

I unplugged it and tried starting the car, car cranked but obviously didn't start.

Inspect the wiring/connectors for the crank sensor. Repair if able.
Should be easy to replace the sensor if needed.

 

[RjBlack]

Had the OBD reader on again, it has a live data where I’m able to see the revs exactly. Doesn’t look like there’s a discrepancy between live data and dash revs. Assuming this means it isn’t the sensor that’s causing the error? Giving out a p0727 error now also

 

[RjBlack]

Inspect the wiring/connectors for the crank sensor. Repair if able.
Should be easy to replace the sensor if needed.

Wire looks intact, can’t determine anything via visual inspection

 

[Seatman]

Wire looks intact, can’t determine anything via visual inspection

Might need to find out which pin on the ecu plug is which and test the continuity for the sensor, or maybe just try and a new sensor first and see if there's any improvement.
Screwfix sell a failry cheap multimeter, think it's about £14 or so.