Post by tipsymcstager on Dec 1, 2011 6:39:38 GMT -6
Throttle Position Sensor replacement, and a good cleaning to boot! you'll see why i took it off in the pic's to clean!
(regardless of any other issues) after a good scrubing you'll feel a better throttle response, and better gas mileage should you choose just to pull it off to clean!
Throttle Position
conditions
Symptoms may include:
Rough idle
High idle
Surging
other symptoms may also be present ( experienced all Symptoms)
Malfunction Indicator Lamp (MIL) illumination (Check Engine Light or Service Engine Soon light)
Intermittent stumble on acceleration or deceleration
A code P0123 may mean that one or more of the following has happened:
TPS has intermittent open or short internally
Harness is rubbing and causing an open or short in the wiring
TPS not mounted securely
Bad connection at the TPS
Bad PCM (less likely)
Faulty TPS
Water or corrosion in connector or sensor
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, carefully inspect all wiring and connectors that lead to the TPS. More than likely the problem is with the TPS wiring. Check the voltage at the TPS (refer to a service manual for your vehicle for this specific information). If the voltage spikes or is too high (over 4.65 volts with key on, engine off), then that is indicative of a problem. Carefully trace each wire from the TPS wiring harness to check for breaks, rubbing against other components, etc.
The TPS (Throttle Position Sensor) is a potentiometer that is mounted to the throttle body. It detects the throttle blade angle. As the throttle blade moves, the TPS sends a signal to the PCM (Powertrain Control Module). Usually a three wire sensor: A 5 volt reference from the PCM to the TPS, a ground from the PCM to the TPS, and a signal return from the TPS to the PCM.
The TPS sends the throttle position information back to the PCM on this signal wire. When the throttle is closed the signal is near .45 volts. At WOT (Wide Open Throttle) the TPS signal voltage will approach a full 5 volts. When the PCM sees a voltage that is outside of normal operating range, P0120 will set.
NOTE: The PCM knows that any large change in throttle position means a cooresponding change in manifold pressure (MAP). On some models the PCM will monitor MAP and TPS operation for comparison. Meaning that if the PCM sees a large percentage change in throttle position, it expects to see a cooresponding change in manifold pressure and vice versa. If it doesn't see this comparitive change, P0120 may set. This doesn't apply to all models.
A code P0120(1&2) may mean that one or more of the following has happened:
Sticking throttle return spring
MAP or TPS connector corrosion
Misrouted harness causing chafing
Bad TPS
Bad PCM
If you have access to a scan tool, with KOEO (Key on engine off) observe the TPS voltage. With throttle closed, voltage should be about .45 volts. It should gradually sweep upwards to approximately 4.5 to 5 volts as you depress the throttle. Sometimes only a scope can capture an intermittent glitch in the TPS signal voltage. If you notice a glitch in the TPS sweep voltage, replace the TPS.
NOTE: Some TPS sensors require fine adjustment. If you aren't comfortable with using a DVOM (Digital Volt Ohm meter) to adjust the new TPS, then it's best to take the vehicle to a shop. If the voltage is not .45 volts (+or- .3 volts or so) with the throttle closed or if the reading is "stuck" then unplug the TPS connector. With KOEO check for 5 volts reference voltage present at the connector and a good ground. You can check the signal circuit for continuity by jumping a fused wire between the ground circuit of the TPS connector and the signal circuit. If the TPS reading on the scan tool now reads zero, then replace the TPS. However if that doesn't change the reading to zero, then check for an open or a short on the signal wire and if none is found, suspect a bad PCM. If manipulating the TPS wiring harness causes any change in idle, then suspect bad TPS.
If you have access to a scan tool, with KOEO (Key on engine off) observe the TPS voltage. With throttle closed, voltage should be about .45 volts. It should gradually sweep upwards to approximately 4.5 to 5 volts as you depress the throttle. Sometimes only a scope can capture an intermittent glitch in the TPS signal voltage. If you notice a glitch in the TPS sweep voltage, replace the TPS.
OBD-Codes.com
Your OBD-II Trouble Codes Repair Site
---------------------------------------------------------------------------------
and there was my issue (in yellow) at the end of this i will post a nice "how to Adjusting the Idle" site i found sometime ago!
lets get started
remove the air box cover, pulling the sensor connectors first.
now that we've made a little room we need to take off the throttle and cruise cables off the return spring/butterfly
the cruise cable just clips off/on, open the butterfly all the way and pull the cable out a little from the sleeve, tilt it down and push off!
next is the Throttle cable you'll need two hands for this so jam something in the return spring to hold in place!
again, get some slack on the cable. and get it off the lever mechanism. and slid the bung out of it's slot.
-----------------------------------------------------------------------------------
Throttle body comes off next, for the LX5 it's just a 10mm
if your working on a 4.0, it a torx but all the above still applies!
remove the return spring cable bracket, by the two bottom nuts that also hold the body on, and the top 10mm nut.
-----------------------------------------------------------------------------------
ok, back topside you'll need to get the vacuum lines off be very
careful that small line can be very brittle and crack,when subjected to pressure!!!!
so just pop them off at the boot and move the out of the way, and as little as possible!
---------------------------------------------------------------------------------
now pop off the connectors for the two sensors, and that last 10mm nut above the barcode tag in the pic and the body is ready to come off!
-----------------------------------------------------------------------------------
THIS, is why i took it off!!
after only 115k i really think it needed a good cleaning!
any gasket in on the intake side needs to come off, and a light sanding with some fine steelwool will do.
a paper towel, or bunched ou rag in the intake will keep any debris out
(some handy tools for the job)
---------------------------------------------------------------------------------
heres the TPS & IAC off, and body ready for cleaning!
you'll need a torx (not sure what size, sorry)
----------------------------------------------------------------------------------
another fine tool to help the job along.................LOL
----------------------------------------------------------------------------------
a good carb, choke & TB cleaner! a brass wire brush work well
(do this outside)
be sure to get the edge of the butterfly, the IAC inlet and all the cavities.
then a light sanding with the fine steelwool on the gasket surface
and your done
---------------------------------------------------------------------------------
well not much more then that to it!
after the TB is clean, and the sensors are back on she go's back on the car, the same way it came off!
-----------------------------------------------------------------------------------
some part numbers for ya, and that "Adjusting the Idle" site
2001-2002
TPS ACDELCO Part # 213912
gasket FEL-PRO Part # 61304
www.240sx.org/faq/articles/throttle_position_sensor_adjustm.htm
(regardless of any other issues) after a good scrubing you'll feel a better throttle response, and better gas mileage should you choose just to pull it off to clean!
Throttle Position
conditions
Symptoms may include:
Rough idle
High idle
Surging
other symptoms may also be present ( experienced all Symptoms)
Malfunction Indicator Lamp (MIL) illumination (Check Engine Light or Service Engine Soon light)
Intermittent stumble on acceleration or deceleration
A code P0123 may mean that one or more of the following has happened:
TPS has intermittent open or short internally
Harness is rubbing and causing an open or short in the wiring
TPS not mounted securely
Bad connection at the TPS
Bad PCM (less likely)
Faulty TPS
Water or corrosion in connector or sensor
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, carefully inspect all wiring and connectors that lead to the TPS. More than likely the problem is with the TPS wiring. Check the voltage at the TPS (refer to a service manual for your vehicle for this specific information). If the voltage spikes or is too high (over 4.65 volts with key on, engine off), then that is indicative of a problem. Carefully trace each wire from the TPS wiring harness to check for breaks, rubbing against other components, etc.
The TPS (Throttle Position Sensor) is a potentiometer that is mounted to the throttle body. It detects the throttle blade angle. As the throttle blade moves, the TPS sends a signal to the PCM (Powertrain Control Module). Usually a three wire sensor: A 5 volt reference from the PCM to the TPS, a ground from the PCM to the TPS, and a signal return from the TPS to the PCM.
The TPS sends the throttle position information back to the PCM on this signal wire. When the throttle is closed the signal is near .45 volts. At WOT (Wide Open Throttle) the TPS signal voltage will approach a full 5 volts. When the PCM sees a voltage that is outside of normal operating range, P0120 will set.
NOTE: The PCM knows that any large change in throttle position means a cooresponding change in manifold pressure (MAP). On some models the PCM will monitor MAP and TPS operation for comparison. Meaning that if the PCM sees a large percentage change in throttle position, it expects to see a cooresponding change in manifold pressure and vice versa. If it doesn't see this comparitive change, P0120 may set. This doesn't apply to all models.
A code P0120(1&2) may mean that one or more of the following has happened:
Sticking throttle return spring
MAP or TPS connector corrosion
Misrouted harness causing chafing
Bad TPS
Bad PCM
If you have access to a scan tool, with KOEO (Key on engine off) observe the TPS voltage. With throttle closed, voltage should be about .45 volts. It should gradually sweep upwards to approximately 4.5 to 5 volts as you depress the throttle. Sometimes only a scope can capture an intermittent glitch in the TPS signal voltage. If you notice a glitch in the TPS sweep voltage, replace the TPS.
NOTE: Some TPS sensors require fine adjustment. If you aren't comfortable with using a DVOM (Digital Volt Ohm meter) to adjust the new TPS, then it's best to take the vehicle to a shop. If the voltage is not .45 volts (+or- .3 volts or so) with the throttle closed or if the reading is "stuck" then unplug the TPS connector. With KOEO check for 5 volts reference voltage present at the connector and a good ground. You can check the signal circuit for continuity by jumping a fused wire between the ground circuit of the TPS connector and the signal circuit. If the TPS reading on the scan tool now reads zero, then replace the TPS. However if that doesn't change the reading to zero, then check for an open or a short on the signal wire and if none is found, suspect a bad PCM. If manipulating the TPS wiring harness causes any change in idle, then suspect bad TPS.
If you have access to a scan tool, with KOEO (Key on engine off) observe the TPS voltage. With throttle closed, voltage should be about .45 volts. It should gradually sweep upwards to approximately 4.5 to 5 volts as you depress the throttle. Sometimes only a scope can capture an intermittent glitch in the TPS signal voltage. If you notice a glitch in the TPS sweep voltage, replace the TPS.
OBD-Codes.com
Your OBD-II Trouble Codes Repair Site
---------------------------------------------------------------------------------
and there was my issue (in yellow) at the end of this i will post a nice "how to Adjusting the Idle" site i found sometime ago!
lets get started
remove the air box cover, pulling the sensor connectors first.
now that we've made a little room we need to take off the throttle and cruise cables off the return spring/butterfly
the cruise cable just clips off/on, open the butterfly all the way and pull the cable out a little from the sleeve, tilt it down and push off!
next is the Throttle cable you'll need two hands for this so jam something in the return spring to hold in place!
again, get some slack on the cable. and get it off the lever mechanism. and slid the bung out of it's slot.
-----------------------------------------------------------------------------------
Throttle body comes off next, for the LX5 it's just a 10mm
if your working on a 4.0, it a torx but all the above still applies!
remove the return spring cable bracket, by the two bottom nuts that also hold the body on, and the top 10mm nut.
-----------------------------------------------------------------------------------
ok, back topside you'll need to get the vacuum lines off be very
careful that small line can be very brittle and crack,when subjected to pressure!!!!
so just pop them off at the boot and move the out of the way, and as little as possible!
---------------------------------------------------------------------------------
now pop off the connectors for the two sensors, and that last 10mm nut above the barcode tag in the pic and the body is ready to come off!
-----------------------------------------------------------------------------------
THIS, is why i took it off!!
after only 115k i really think it needed a good cleaning!
any gasket in on the intake side needs to come off, and a light sanding with some fine steelwool will do.
a paper towel, or bunched ou rag in the intake will keep any debris out
(some handy tools for the job)
---------------------------------------------------------------------------------
heres the TPS & IAC off, and body ready for cleaning!
you'll need a torx (not sure what size, sorry)
----------------------------------------------------------------------------------
another fine tool to help the job along.................LOL
----------------------------------------------------------------------------------
a good carb, choke & TB cleaner! a brass wire brush work well
(do this outside)
be sure to get the edge of the butterfly, the IAC inlet and all the cavities.
then a light sanding with the fine steelwool on the gasket surface
and your done
---------------------------------------------------------------------------------
well not much more then that to it!
after the TB is clean, and the sensors are back on she go's back on the car, the same way it came off!
-----------------------------------------------------------------------------------
some part numbers for ya, and that "Adjusting the Idle" site
2001-2002
TPS ACDELCO Part # 213912
gasket FEL-PRO Part # 61304
www.240sx.org/faq/articles/throttle_position_sensor_adjustm.htm
