TPS wire into the cabin.

[broxma]

So I have been having some electrical problems due to 20 year old connectors and wiring I assume. I traced the TPS signal, not the 5v or the ground, the signal wire, back into the cabin through the firewall. I found that the TPS signal wire enters into what appears to be the dashboard subharness. I have checked resistance from the pin at the ECU (84 in the case of the EVO ECU, 19 factory) and got a pretty high variable reading. I would have assumed the TPS signal would have run straight back to the ECU uninterrupted.

Anyone know why the TPS signal would run into the subharness then back out? Maybe for the Boost light thing? Anyone know if the resistance from the signal wire at the connector to the ECU should be zero with no power in the car? The TPS wiring diagram (Pin 2 on the connector) shows an intermediate connection to the TPS signal but it's hard to figure intermediate connections from that diagram. Just trying to be certain before I wrap the harness back up and finish soldering the new wires.

/brox

 

[Hertz]

ETACS/cruise control?

 

[chrisfullwood]

You have to check resistance, with the power off. because otherwise you will fry stuff. If you do some searching you can test to see what the readings should be on the sensor, and at the other end of the harness, there shouldn't be a huge difference. If you are noticing a massive difference from at the sensor, and at the wire your checking, then you could have damage, fraying or just old wires. but resistance shouldn't change that much along the wire, maybe an ohm or less, per break in the wire. (break being, a physical connector)