Difficulty starting with ECM-201A and ECM-2000 codes

ddmd · Post by **ddmd** » 18 Feb 2019, 17:33

Hi Everyone. I can use some help. I have a 2000 V70 XC with 202,000 miles.
I experienced a sudden difficulty starting (long normal sounding cranking, starts after several tries)
along with a CEL. Once running, it seems to run normally. Prior to this, starting was easy and reliable.
A VIDA diagnostic check revealed the following codes:
ECM-201A Thermostat - Faulty signal
ECM-2000 Engine coolant temperature (ECT) sensor - signal too low

Under related CSC in VIDA for the ECT sensor, it describes difficulty starting "Engine hard to start/cranks slowly,
Unsure when/at all times"

Does anyone know what the relation is between the ECT sensor and starting? Also, in my case, the cranking
is normal (rapid), not slow.

Post by **abscate** » 18 Feb 2019, 17:48

The sensor and wiring can go bad, which then screws up the injection amount sent by the. Engine control module, or ECM. This gives the hard start or even no start

Your 1999 uses a 3 year only ECT part 9125463

If you search that part number, you should find a thread where the resistance measurements are listed for testing, if you know how to use a volt ohm meter

ddmd · Post by **ddmd** » 18 Feb 2019, 18:14

Thanks for the quick reply. I'm glad that there's an explanation that makes sense. I found the resistance chart
and will check it.

ddmd · Post by **ddmd** » 18 Feb 2019, 20:21

It looks like it's the ECT sensor. It measures >6K ohms at both 0 deg C and 20 deg C.
Thanks for the help! I appreciate it.

Post by **abscate** » 19 Feb 2019, 02:03

You should go OEM on that part, or find one from a runner in a junkyard

Aftermarket reportedly often don't work well.

ddmd · Post by **ddmd** » 19 Feb 2019, 22:07

Thanks. Yes I did order the OEM parts. Hopefully they'll arrive in a day or so.