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1994 Oldsmobile Bravada Repair Question


Topics covered: Rpm, Sensor.
Mileage: 146,000 miles.

Asked on July 16, 2012

What could be causing an analyzer to read a dropping voltage fromthe throttle position sensor as the RPM increases?

I have replaced the TPS three times and the PCM yet the analyzer still continues to say the TPS is bad and shows the voltage dropping as I increase the RPM. It doesn't shift until above 2500 RPM and then shifts very hard. It also is running 200 RPM faster than normal at highway speeds even though it is in OD.
Avatar Asked by PaulHomerJr

Answer

Replied on July 16, 2012

What code is comming up?

Tiny Answered by Docfixit (expert)
18,420 answers provided
Replied on July 16, 2012

22 TPS Sensor Low

Tiny Response from PaulHomerJr
1 question asked
Replied on July 16, 2012

Will need a DVOM see diagrams back probe TPS connector Black lead on bottom sensor ground and middle one RED probe. Key on at idle voltage less than 1 volt(.5 v best). then operate throttle from idle to full meter should go up steady to 4.5 V

Tiny Answered by Docfixit (expert)
18,420 answers provided

Replied on July 16, 2012

opps

Tiny Answered by Docfixit (expert)
18,420 answers provided
Replied on July 16, 2012

It starts out at.27 and drops as the throttle is opened.

Tiny Response from PaulHomerJr
1 question asked
Replied on July 16, 2012

Check reference voltag must be 5V

Tiny Answered by Docfixit (expert)
18,420 answers provided

Replied on July 16, 2012

Reference voltage is 5.02. Checked the ground and it's fine also. The low voltage has been the same for all 3 new TPS.

Tiny Response from PaulHomerJr
1 question asked
Replied on July 16, 2012

Makes no sence if have 5v REF all TPS is a variable resistor so you say at idle .27v and as open throttl goes to zero

Tiny Answered by Docfixit (expert)
18,420 answers provided
Replied on July 16, 2012

My point exactly. Could this be an issue with one of the tranny sensors?

Tiny Response from PaulHomerJr
1 question asked
Replied on July 16, 2012

Unplug tps use jumper wire from 5v ref and then jumper ground on bottom wire hook up meter across ground and TPS signal open throttle what does it do?

Tiny Answered by Docfixit (expert)
18,420 answers provided