Mechanics

MODELS TPS VALUES

1990 Plymouth Other

Electrical problem
1990 Other Plymouth Models 4 cyl Front Wheel Drive Manual 122500 miles

I recently purchased a 90 Laser at auction. The engine runs great, trans is nice, everything is OK, but the engine light is on, and I need to turn it off for emission purposes. The code reader shows
13, 15, 21, and 25. I have replaced the temp sensor, tried a second intake sensor for the Baro, air temp codes. Running the ohms test on the TPS shows a lo read of 234 ohms, and hi at 5600. The book says low should be 1100, and high 5600. Is the sensor bad?
Avatar
OldLaser
July 8, 2008.



I don't have the ohm spec, but it looks out to me.

Mitchell shows the voltage between .48 and .52 with this procedure:


http://www.2carpros.com/forum/automotive_pictures/30961_laz_1.jpg


Thanks for the reply. The Haynes manual I have shows the same (4.8 - 5.2) signal voltage, and that reads correct on the multimeter. At 4.92 on the scale at the harness connector. The ohms have been the only question mark I have seen, with the hi side OK and the low side being well below spec.

Tiny
OldLaser
Jul 8, 2008.
I assume you have disconnected battery and then ran engine to see if same codes show up?

Docfixit
Jul 8, 2008.
Using a Snap On M2500, the codes were 13, 15, 21, and 25.
21 was the temp sensor. The ohms dropped like a hammer, so it has been replaced. Idle changed, but code still apears.
15 is the TPS and/or the Idle Speed Control. The TPS has issues. The ohm range is off, and off the car appears to have drops throughout the movement (saw that tonight). It will go from 3.7 to a 3.2, and back to 3.7, and at one time dropped from 5.2 to 1.9 and back. The drops are repeatable.
13 and 25 are in the air intake mechanism. The ohms check and signal feed appear normal, but the Baro sensor reads 37.9. My Haynes book says 29.9 at sea level and drops with elevation. I tried a second air intake assembly from a junk yard, and the Baro had the same reading.

Tiny
OldLaser
Jul 9, 2008.