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Jeremiah Mahler
Jeremiah Mahler, ASE Certified Technician
Category: VW
Satisfied Customers: 200
Experience:  ASE Master Certified with advanced L1, California Smog Tech, Volkswagen Certified
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2002 volkswagen jetta gls: EPC light came..60 mph..wierd

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EPC light came in on 2002 volkswagen jetta gls (2.0 L) then the car would not go over 60 mph, and was ideling wierd. Car has since been idling weird and check engine light has been blinking and doesnt start very well
When the check engine light is "blinking" this means there is a severe problem that may cause damage to the engine and/or catalytic converter.
The fact that its performance is poor confirms there is a severe problem.

It is hard to say what is wrong without knowing what codes are stored.
Some possibilities are: spark plug wires, spark plugs, MAF, O2 sensor, ...

You can usually get the codes read for free at auto parts stores but it only reads the engine control module. Since the EPC light is on there may be codes in other modules. To read these other modules you would need to use a factory scan tool (or VAG-COM). Finding out what codes are stored in the engine control module would be the first step in diagnosing your problem.
Customer: replied 8 years ago.
Another menchanic prevould mentioned that replacng the speed sensor may be needd in the future, culd that be related?

What do you thnk the EPC light s indicating?
It is possible it could be the engine speed sensor, those go out a lot too. Usually they cause the engine to sporadically die.

It is hard to say what the EPC light is indicating without knowing the codes. It could be because of the engine problems or it could be something else.
Customer: replied 8 years ago.

Thanks for the info, we hooked up to the code computer,, here is what we got


P0300 Randon Multiple Cylinder Misfire Detected

P0307 Cylinder 1 Misfire detected

P0322 Ignition/Dist Engine Speed Input Circuit No Signal

P0321 Ignition/Dist Engine Speed CKT Range/Perf

P0725 Engine Speed Sensor Circuit Malfunction


any suggestions

It looks like the engine speed sensor is the biggest problem.
The misfire is likely the result of a problem with the engine speed sensor.

I would check the engine speed sensor wiring and replace the sensor if no problems were found.

No information about the EPC problem in these codes, it is in a different module.
But definitely get the engine speed sensor fixed.
Customer: replied 8 years ago.
thanks for the info, is it OK to drive until we get it fixed?
You could drive it but it might die and leave you stranded.
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Customer: replied 8 years ago.
Customer: replied 7 years ago.
Local Mechanic fixed the speed sensor, along with about every other sensor known, as well as the distributor. The Car is still having issues and doesnt start itermitantly. We are no at a loss as to what we should do. The Mechanic is at his wits end and doesnt know how to fix whatever the problem is... well, first he can find the problem.... any suggestions on what to do next...?
If it is not a sensor it could be a problem with the wiring between the sensor and the ECM. At this point I would look at the signals to and from the sensors in detail using a scope. Doing this should find any sporadic or marginal signals.