88 GT (3.4l crate - swap done a couple years ago, auto)

Code 22, replaced TPS (new AC Delco unit)

Measuring 5v on grey wire at sensor, check black wire continuity to ground and that is good.

Engine off, key on scanner reads 0.13. Scanner reads 0.15 with engine at idle. Checked with a voltage meter and getting 0.156v (engine off)

Original TPS gave the same readings.

Max reading (WOT) on TPS signal wire 4.82v on meter (engine off).

opinions?? Bad TPS (both)?? Check engine light came on after gas stop after a long drive.


edit: to add there is no "adjustment" on either sensor (holes are not slotted) - well I could bend the arm, but shouldn't have to.

[This message has been edited by Mickey_Moose (edited 09-23-2015).]

Dont remember what code 22 is

Throttle Position Sensor (TPS low voltage)
Code 22 indicates a problem with the Throttle Position Sensor.

a dirty connector or broken wire will throw the code.

quote Originally posted by 2.5: Dont remember what code 22 is

Sorry, guess I should have put that in there - but answered above.

quote Originally posted by Gall757: Throttle Position Sensor (TPS low voltage) Code 22 indicates a problem with the Throttle Position Sensor. a dirty connector or broken wire will throw the code.

Thanks will disassemble the connector tonight and try cleaning the pins - I figure the wiring is good since I read the same voltages at the ECM or right at the connector.

Edit - guess everyone already has a plus from me, so I couldn't add one for offering help.

[This message has been edited by Mickey_Moose (edited 09-24-2015).]

quote Originally posted by 2.5: Dont remember what code 22 is

You're not familiar with this page? ECM Codes

Shame on you.

quote Originally posted by Patrick: You're not familiar with this page? ECM Codes Shame on you.

True.

quote Originally posted by Patrick: Have you tried putting an ohmmeter on it (while disconnected from the harness)? It'll show if there's a bad spot in the windings. An even easier way to test the TPS is if you have a scanner or use WinALDL. With key on (but the engine not running) you can see the voltage change as you move the throttle through its full range.

...but yes there is a voltage change - the problem is that it is too at the start (FSM says 0.2v).

quote Originally posted by Mickey_Moose: Engine off, key on scanner reads 0.13. Scanner reads 0.15 with engine at idle. Checked with a voltage meter and getting 0.156v (engine off)

Update: well looks like the issue is with the TPS sender - fed 5v and ground into the sender, measure output (direct connections to the sender) - reads 0.15v, so I just applied a "plyer mod" to the arm and now it reads 0.21v on the scanner (just over the threshold). See how that goes. that being said, what should the "normal" reading be at idle (or key ON at rest)?

For the record I put the old sender back in and it is now reading 1.8v at key on - so just tossed it.

[This message has been edited by Mickey_Moose (edited 09-25-2015).]

quote Originally posted by Mickey_Moose: ... what should the "normal" reading be at idle (or key off at rest)?

With key "off", wouldn't it be zero volts?

quote Originally posted by Patrick: With key "off", wouldn't it be zero volts?

....you sir are correct, my mistake that should have read key ON - fixed.

quote Originally posted by Mickey_Moose: ....that should have read key ON - fixed.

TPS adjustment shouldn't be necessary, but the "ideal" reading would be .5-.6v with the throttle closed.

quote Originally posted by Patrick: TPS adjustment shouldn't be necessary, but the "ideal" reading would be .5-.6v with the throttle closed.

I agree it shouldn't be, but I don't really want to buy another sender just yet - so I will see how it goes with the modification.

Thanks for the info.