While driving my CEL illuminated, then while trying to park the D4 started flashing on my instrument panel and shuddered while trying to go in reverse. Put it in park and then tried reverse again, no problem 2nd try, D4 still flagging. Later on moved my car and D4 was no longer flashing, drive fine, CEL still illuminated. Honda dealer said I need the AT range gear position switch replaced. D4 no longer flashing and driving fine. Thoughts? Safe to drive? Why did it flash 1 time and then stop? How did the dealer know what needs to be replaced if it was no longer flashing?! Is it a code from the CEL?

 

Mechanic told me to replace neutral safety switch, does that sound right?!

 

You didn't state year or submodel/engine you have.
Depending on what year you have the way to retrieve the code(s) is slightly different.

 

2002 accord lx, 4cyl

 

Best is to beg/borrow/steal(rent) an OBDII code reader.
Plug it into your OBDII port turn ignition to II(ON) and follow code readers instructions.
Most generic code readers have garbage descriptions, ignore them.
Only record the actual code(s). They will be formatted >" P#### "
Post the code(s) here for further diagnostics.

 

p0325 & p1705 from a Honda dealer, the dealer said to replace both the knock sensor and range gear position switch. I asked a transmission shop and they said to replace the neutral safety switch. I don’t know much about cars and want to make sure I’m doing the right thing and not spending a lot of unnecessary money. Hard times with COVID.

 

Before throwing parts at it, inspect the wire harness for both the KS and Range sensor(AKA NSS).
Range sensor is located on the end of the transmission behind the wheel, P1705 is code for a short to ground. It could be the switch is bad but it could be damage to the wire harness, or if you drove through a big enough puddle you may have flooded the switch.
Verify any wires and connections are clean and tight.
If any work was done recently, recheck it.
Verify nothing looks out of place or damaged wires.