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Discussion Starter #1
1997 TL1000S "V"
Fault: Low voltage reading through pressure sensors

With ignition "ON" voltage checked with voltmeter between RED(+) - Black/Brown(-), voltage reading shown as 0.23V

The manual shows the voltage as being between 4.5V-5V.. My pinout for the electrical connector on the IAP sensor is RED-Black/Brown-BROWN
The pinout for the electrical connector on the AP sensor is RED-Black/Brown-VIOLET

The wiring diagram in the manual leads to conflicting information, wiring diagram shows RED-BROWN-B/BR and RED-VIOLET-B/BR respectively.. According to the manual, if the voltage is not within spec of the manual the ECU should be replaced. Is there a way to test the ECU without buying a new unit immediately? The wiring direction is very ambiguous, hopefully someone can clarify this for me.. I appreciate all help, and look forward to determining if anyone else is having this problem.
 

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1997 TL1000S "V"
Fault: Low voltage reading through pressure sensors

With ignition "ON" voltage checked with voltmeter between RED(+) - Black/Brown(-), voltage reading shown as 0.23V

The manual shows the voltage as being between 4.5V-5V.. My pinout for the electrical connector on the IAP sensor is RED-Black/Brown-BROWN
The pinout for the electrical connector on the AP sensor is RED-Black/Brown-VIOLET

The wiring diagram in the manual leads to conflicting information, wiring diagram shows RED-BROWN-B/BR and RED-VIOLET-B/BR respectively.. ......
For starters, are you using the factory Suzuki service manual or an aftermarket manual, like Hanes? The downloadable PDF Suzuki manual shows the correct color code and pinout, as far as I can see. On page 4-37 in the TLS manual, it shows the IAP sensor wires as RED-BLACK/Brn-BROWN, and that agrees with the actual IAP sensor connector on my TLS.

Just for reference, so you know what you are looking at:
  • The RED wire is the +5V supply that comes from the ECM. It provides power to all of the FI sensors that requre +5V.
  • The BLACK/Brn wire is the dedicated 'ground' circuit for the FI sensor network. Electrically, it is essentially the same potential as the bike's chassis ground (Black/White wire network), but it is isolated in the EMC in such a way to reduce ignition noise and electrical fluctuations that could cause problems for the fuel injection control circuits.
  • The BROWN wire at the IAP sensor (and the VIOLET wire in the case of the AP sensor) is the output from the sensor. It provides the feedback voltage to the ECM based on the pressure applied to the sensor's port.
Concerning the low voltage you measured from the Red wire to the Black/Brn, don't get too excited about the ECM until you confirm that the Red wire is not shorting to chassis ground somewhere. With the key off, use your ohm meter to measure between the Red and chassis ground. If you get a low reading, disconnect the ECM from the loom and measure it again. Any change?
NOTE: Be sure to disconnect the battery BEFORE connecting and disconnecting the ECM from the loom.

Hopefully, this helps a little. :) Let us know what you find please.
 

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UPDATE:

I had my multimeter setup to measure current, therefore all readings were erroneous.. I corrected the multimeter and all voltages for TPS, IAP, and AP sensors are within specs. I am very disappointed however, as I thought I finally found my main problem for the engine running so poorly. I will create a new thread in hopes of receiving diagnosis help, as well as sharing my experience with others. I appreciate your response anyway, thank you for the pictures and advice.
 
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