Mechanics

91 PARK AVE ULTRA TPS

1991 Buick Park Avenue • 6 cylinder FWD Automatic •

I have a 91 buick park ave ultra. I read the codes and one came up for the TPS- low voltage. I bought a new one and would like to know the proper procedure for installing it. When I am driving the car it surges even when driving at a steady speed. When I am at a stop and accelerate to take off it sometimes wants to stall especially if I try to accelerate too quickly. Could that be caused by the TPS?
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Ldiane29
December 12, 2010.



Just because you have a code for low tps voltage doesn't mean a new tps sensor will fix it. You could have a terminal tightness issue wire problem ground issue or even a computer issue. You need to rent a scanner that will read live engine data on your car. Also what is the code number you have I need the number itself.


Saturntech9
Dec 12, 2010.
The code was 22


Tiny
Ldiane29
Dec 12, 2010.
I posted the trouble for that code along with a wire diagram for the tps. Here is the code description for it as well.
CIRCUIT DESCRIPTION: The Throttle Position Sensor (TPS) provides a voltage signal that changes relative to throttle blade angle. Signal voltage will vary from about 0.4 at idle to about 5 volts at wide open throttle. The TPS signal is one of the most important inputs used by the PCM for fuel control and for most of the PCM control outputs.

Code 22 will set if the ignition key is "ON" and the TPS signal voltage is less than 0.2 volt for 4 seconds.

TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart.

1. Determines if conditions necessary to set a code 22 exist.
2. Simulates Code 21: (high voltage) If PCM recognizes the high signal voltage and sets a code 21, the PCM and wiring are OK.
3. With closed throttle, ignition "ON" or at idle, voltage at "BB10" should be 0.33 - 0.46 volt. If not, check adjustment. If adjustment does not correct voltage output, replace TPS.
4. Simulates a high signal voltage. Checks CKT 417 for an open.

DIAGNOSTIC AIDS: * "Scan" tool reads throttle position in volts. Voltage should increase at a steady rate as throttle is moved toward WOT. Also some "Scan" tools will read throttle angle as a percentage: 0% = closed throttle; 100% = WOT
* An open or short to ground in CKTs 416 or 417 will result in a Code 22.

If circuit 417 is open or grounded when the vehicle engine is started a high idle may result. A scan tool may read the following.

* TPS = 0.4 volt or less.
* RPM > 1000 in park.
* Desired idle = 725.
* IAC counts > 40
* SES light "ON." Code 22 set.

If the intermittent is repaired without cycling the key "OFF" the Scan may read the following.

* TPS = 0.42 volts or less.
* RPM > 1500 in park.
* Desired idle = 725.
* IAC counts > 55
* SES light "OFF".

Check for: * Poor Connection or Damaged Harness. Inspect PCM harness connectors for backed out terminal "BB10, " improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.
* Intermittent Test. If connections and harness check OK, monitor TPS voltage display while moving related connectors and wiring harness. If the failure is induced, the display will change. This may help to isolate the location of the malfunction.
* TPS Scaling. Observe TPS voltage display while depressing accelerator pedal with engine stopped and ignition "ON." Display should vary from closed throttle TPS voltage when throttle was closed, to over 4.5 volts (4500 mV) when throttle is held at wide open throttle position.


Saturntech9
Dec 12, 2010.