2000 Impala P0122 code, how do I remedy this?

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#1
V6 3.8 has 106, 000 miles, 51, 000 on the new motor...I just replaced the alternator,radiator(leaked), fuel filter, then finally the TPS because it started but then idled low then would just shutoff, I just got a code P0122 (B) ...now it idles at high rpms and won't shift to go faster than 45mph...help what now can I do for the P0122 code? By the way there was a (B) after the P0122 is that a part of the code as well?
 
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#2
PO122 is a tps code..low voltage...did you check the wiring and the connector?....was the tps oem?...it could be a bad tps....Jim
 
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#4
Terminals and harness....here is a diagram if you want to check voltage....Jim............
The Throttle Position (TP) sensor is a potentiometer connected to the throttle shaft on the throttle body. By monitoring the voltage on the signal line, the PCM calculates throttle position. As the throttle valve angle is changed (accelerator pedal moved), the TP sensor signal also changes. At a closed throttle position, the output of the TP sensor is low. As the throttle valve opens the TP sensor voltage increases so that at Wide Open Throttle (WOT) , the TP sensor voltage should be above 4 volts . The PCM calculates fuel delivery based on throttle valve angle (driver demand).

A broken or loose TP sensor may cause intermittent bursts of fuel from an injector and unstable idle because the PCM thinks the throttle is moving. A hard failure in the TP sensor 5 volts reference or signal circuits will set either a DTC P0122 or DTC P0123. A hard failure with the TP sensor ground circuit will set DTCs P0123 and P0117. Once a DTC is set, the PCM will use an artificial default value based on engine RPM and mass air flow for throttle position and some vehicle performance will return. A high idle may result when either DTC P0122 or DTC P0123 are set.

The PCM can detect intermittent TP sensor faults. DTC P1121 or DTC P1122 will set if an intermittent high or low circuit failure is being detected. The PCM can also detect a shifted TP sensor. The PCM monitors throttle position and compares the actual TP sensor reading to a predicted TP value calculated from engine speed. If the PCM detects an out of range condition, DTC P0121 will set.


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#7
Did you check it with it closed and WOT?....here is a diagram that might help you....Jim.......
The Throttle Position (TP) sensor is a potentiometer connected to the throttle shaft on the throttle body. By monitoring the voltage on the signal line, the PCM calculates throttle position. As the throttle valve angle is changed (accelerator pedal moved), the TP sensor signal also changes. At a closed throttle position, the output of the TP sensor is low. As the throttle valve opens the TP sensor voltage increases so that at Wide Open Throttle (WOT) , the TP sensor voltage should be above 4 volts . The PCM calculates fuel delivery based on throttle valve angle (driver demand).

A broken or loose TP sensor may cause intermittent bursts of fuel from an injector and unstable idle because the PCM thinks the throttle is moving. A hard failure in the TP sensor 5 volts reference or signal circuits will set either a DTC P0122 or DTC P0123. A hard failure with the TP sensor ground circuit will set DTCs P0123 and P0117. Once a DTC is set, the PCM will use an artificial default value based on engine RPM and mass air flow for throttle position and some vehicle performance will return. A high idle may result when either DTC P0122 or DTC P0123 are set.........



..
 

Gus

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#8
Looking at the diagram provided for you, "C" should be 5.0 volts, "A" should be ground, and "B" should be the signal to the PCM...with key on, and engine off, backprobe "B" with a voltmeter.....should be under a volt at closed throttle.....as you slowly open the throttle it should linearly increase to over 4.0 volts at wide open throttle....

If it does this, and the code still sets, you either have a wiring problem(at harness connector to TPS or at the connector to the PCM) or a PCM problem...one place to check is the PCM......it is located in the air box(remove air filter and split the box...usually two screws).....have seen critters nest in there and eat the wires...
 
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#9
I didn't check it at the PCM because it started and idled correctly, it ran one day perfectly...then today it would turn over and start then idle low then shut off. I can get on the gas a little to get it to run, but as soon as the rpms drop...it shuts off. Could it the tps or connections come loose or ??? I got to the PCM, but there what looks like two "computer" parts...where do I hook up to check the volts?