I've had both of these codes before and neither affect how the car drives.In the meanwhile, I'd like to trick my PM7 ECU into not throwing codes 17 and 20.
17 - Vehicle speed sensor:
On my car this ecu wire is simply cut, and there's no actual sensor (it's a 1986 car). According to this article, the VSS signal to the OBD0 ECU pin is a pulsed short to ground: Honda VSS Engineering Analysis
From reading the article, I thin I might fool the ECU by shorting the pin to ground with some big resistor (so I don't melt the circuit).
Can anyone confirm this is an ok idea?
Alternatively, I could make up some simple electronic switching circuit, or fabricate and actual speed sensor out of a magnetic reed switch (getting too difficult here)
20 - Electric load detection:
I have no idea about this one. Anyone knows what the signal on the ECU pin is supposed to look like?
Possibly short it to ground via a 820Ohm resistor as well?
Honda Electrical Load Detection (ELD) Bypass - Honda Accord Forum - Honda Accord Enthusiast Forums
Nice find with the MAP sensor. FYI the ELD shouldn't throw a CEL, only the VSS.The ELD will only show a code on the ECU - but no CEL.