MVS Forums member JBRollo:
I have been trying to fix a code P1657 on a 2000 Volvo S70 for about a week. No other symptoms at all. Finally noticed that the ETM warning light was not lighting up on start. I first thought someone cut the wire but I got lucky.
The bulb had been moved to a slot not in use! Moved it back and the code disappeared. Went throught three restarts and a test drive to make sure…think I fixed it. (ETM was replaced soon after I bought it!)
There doesn’t seem to be anything on the web about this code so I’m posting it here.
Code P1657 lookup yields ETS MIL Request OFF Signal Low (MIL ON)
So just check the bulb if you get this. The bottom panel under the drivers dash comes off easily.
Probably applies to other Volvos after 1999. I have the Denso engine management system.
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