'02 DX TPS reference voltage

Hondapocalypse

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Just a quick question regarding the TPS reference voltage. My past experience and everything I have read tells me that the reference voltage from the ECU to the TPS is always 5V on a Honda. The car in question has 10V on the yellow wire to the TPS, and can also confirm that the 10V is straight out of the ECU.

Is 10V correct? Even a few techs at the local Honda dealer couldn't tell me me if it should be 10V instead of 5V. The Helms manual doesn't say anything about it that I can find, and only offers specs for throttle percentage read via scantool.

A big thanks to anyone that can confirm for me what the voltage should be. I am trying to get this car back on the road as quickly as possible.

-KC
 

Hondapocalypse

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every honda I've worked on was 5v.

Whats the code?


Thank you for your input on the reference voltage. Everyone I have dealt with was also 5V, so it really blew my mind to see 10V on that line. There isn't actually a code specific to the TPS present, nor can I force one by disconnecting the TPS with the engine running, which is also unusual in my experience. I have a little time to type at the moment, so let me fill everyone in on the car and what has been done to it.

The car is a bone stock '02 Accord DX with an automatic transaxle. A while back it was dumped nose-first in to a ditch full of standing water, hydrolocking the engine and bending all four rods. (This, of course, was right after the transmission was replaced to the tune of $2K.) I replaced the engine with a used longblock that passed my leakdown test with flying colors, and has cylinder compression of 180-185 across the board. Replaced timing components and water pump. Cleaned all electrical connections under the hood with water dispersing electrical cleaner and replaced forward O2 on principle as it has been bent bit in the accident. Upon initial start-up, misfiring was significant at all engine speeds, and ignition broke up badly above 3k RPM. Codes P0300, P0301, P0302, P0303, P0304, and P1399 were stored.

ICM and coil tested bad (Something about electronics and water not mixing, I suppose). Replaced faulty ICM and coil, along with worn rotor, cap, and plugs. (Wires tested good and do not leak) Cleaned and tested EGR valve. Cleaned intake manifold with special focus on EGR passages. Cleaned throttle body. Engine ran significantly better as a result, and code P1399 did not return, however all other codes returned and general misfiring in all cylinders was still present at idle, though hardly noticeable, (both cold and at normal operating temp), and engine would die returning to idle form any raised RPM. Engine vacuum tested to be 19-20 inches, that is to say, there are no vacuum leaks.This is when I got the idea to check out the TPS.

Proceeded to perform electrical diagnostics between underhood connections and ECU, etc. Everything tests good so far except for the 10V reference to the TPS. The manual gets pretty in depth with chasing wires between the ECU and the distributor, but it seems to be oddly silent when it comes to the TPS.

Of course, all of this is greatly simplified, but it outlines most of what has been done. I just really wanted to know if the TPS should only be getting 5V, because the ECU is clearly faulty if that is the case. I'm trying to avoid guessing that the ECU should be replaced, since it is going to cost at least $100 for another used ECU and $200 on top of that to have the dealership program the thing. Again, the Honda techs were as clueless as I was about the 10V reading, so I figured it was time to stop and get some opinions from others.
 
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