good stuff Joe!
a quickie;
126 MAP above or below normal = Bad MAP sensor, vacuum leak, bad hose to MAP sensor
121 = TPS
DTCs 121,122,123, 124, 125, OBD II Codes P0122 and P0123 - in TSB 94-26-4
Source: by Ford via miesk5 (Al M) at comcast.net
an excerpt;
"...( B) - TROUBLESHOOTING THE TPS
The following is a list of vehicle symptoms which have been associated with the TPS, but can also be related to other vehicle components.
Check engine light
Stalls/quits
Hesitation/stumble
Fast idle
If an EEC error code has identified the TPS as suspect, perform PC/ED Manual pinpoint tests on the TPS.
Testing the TPS in the vehicle electrical circuit:
The TPS is supplied with a 5.0 volt reference signal. As the TPS senses throttle plate rotation, the output voltage changes to a value in the range of 0.4 volts to 4.8 volts depending on vehicle application. A voltmeter, New Generation Star Tester (NGS) or Service Bay Diagnostics System (SBDS) is the recommended test equipment for checking the TPS output.
The reason SBDS or NGS are the preferred tools is that they allow TPS voltage monitoring without disturbing the connector. Many conditions can be caused by loose, dirty, oxidized, or poor connections that may correct themselves for a short time if the connector is disturbed during testing. This can mislead technicians into replacing a TPS that is okay, and the true cause, a bad connection, may return at some future time.Measuring the TPS voltage at idle is key when diagnosing a TPS since most of its operational life is within 10 degrees of idle.
EEC codes for the TPS are intended as a supplemental aid to diagnostics. They do not indicate the root cause since more than one (1) component can set the same code
Codes: 121, "TP inconsistent with air meter",
Could also be affected by EGR flow low Do the test or clean/R&R...
CAUTION:
MANY VOLTMETERS WILL AUTOMATICALLY CHANGE RANGES WHEN MEASURING TPS OUTPUT FROM IDLE TO WOT. WHEN A VOLTMETER IS USED TO MEASURE TPS OUTPUT FROM IDLE TO WOT, THE METER SCALES OR CHANGES RANGES AUTOMATICALLY. THERE MAY BE AN ERRONEOUS METER DISPLAY UNTIL THE VOLTMETER HAS LOCKED TO THE APPROPRIATE VOLTAGE READING. THE ERRONEOUS METER DISPLAY DOES NOT REPRESENT A DEFECTIVE TPS.
NOTE: IT IS RECOMMENDED THAT THE "RANGE LOCK" FEATURE ON MANY METERS BE SET FOR CHECKING TPS VOLTAGE.
Use the 0.00 range to measure TPS voltage.
If your voltmeter does not change ranges automatically and the meter is set to millivolt scale when reading full range voltages, the meter display may not indicate a valid value. This can be misinterpreted as an open circuit or suspect TPS. Ensure the meter is set to volts for measuring full range voltage levels.
327 EVP circuit below minimum voltage
EVP = testing/descrption etc.
DIAGNOSTIC TROUBLE CODE (DTC) 32/328: CHECK EVP SENSOR AND EGR VALVE OPERATION
DTC 32/328 in Key On Engine Off (KOEO) and Key On Engine Running (KOER) indicates that the EGR valve and/or EVP sensor voltage is lower than normal in the closed position. The EVP voltage is less than the closed limit voltage of 0.24 volts. Because of the preload of the EVP sensor it is very difficult to determine whether the EGR valve has malfunctioned or the EVP sensor has an abnormally high resistance.
Possible causes:
-- Poor continuity in EVP sensor harness or connectors.
-- Damaged EGR valve.
-- Damaged EVP sensor.
-- Damaged Powertrain Control Module (PCM).
l Key off.
l Disconnect EVP sensor.
l Inspect the connectors at harness and sensor for damaged pins, corrosion, loose wires, etc. Service as necessary.
l Remove vacuum line from EGR valve.
l Exercise EGR valve by applying and releasing vacuum with a vacuum pump.
l Reconnect vacuum line to EGR valve and electrical connector to EVP sensor.
l Rerun Key On Engine Off (KOEO) and Key On Engine Running (KOER) Self-Test.
More id 328 comes up again; but need to go to a service manual or disc
also some Testing by Tomco
a quickie;
126 MAP above or below normal = Bad MAP sensor, vacuum leak, bad hose to MAP sensor
121 = TPS
DTCs 121,122,123, 124, 125, OBD II Codes P0122 and P0123 - in TSB 94-26-4
Source: by Ford via miesk5 (Al M) at comcast.net
an excerpt;
"...( B) - TROUBLESHOOTING THE TPS
The following is a list of vehicle symptoms which have been associated with the TPS, but can also be related to other vehicle components.
Check engine light
Stalls/quits
Hesitation/stumble
Fast idle
If an EEC error code has identified the TPS as suspect, perform PC/ED Manual pinpoint tests on the TPS.
Testing the TPS in the vehicle electrical circuit:
The TPS is supplied with a 5.0 volt reference signal. As the TPS senses throttle plate rotation, the output voltage changes to a value in the range of 0.4 volts to 4.8 volts depending on vehicle application. A voltmeter, New Generation Star Tester (NGS) or Service Bay Diagnostics System (SBDS) is the recommended test equipment for checking the TPS output.
The reason SBDS or NGS are the preferred tools is that they allow TPS voltage monitoring without disturbing the connector. Many conditions can be caused by loose, dirty, oxidized, or poor connections that may correct themselves for a short time if the connector is disturbed during testing. This can mislead technicians into replacing a TPS that is okay, and the true cause, a bad connection, may return at some future time.Measuring the TPS voltage at idle is key when diagnosing a TPS since most of its operational life is within 10 degrees of idle.
EEC codes for the TPS are intended as a supplemental aid to diagnostics. They do not indicate the root cause since more than one (1) component can set the same code
Codes: 121, "TP inconsistent with air meter",
Could also be affected by EGR flow low Do the test or clean/R&R...
CAUTION:
MANY VOLTMETERS WILL AUTOMATICALLY CHANGE RANGES WHEN MEASURING TPS OUTPUT FROM IDLE TO WOT. WHEN A VOLTMETER IS USED TO MEASURE TPS OUTPUT FROM IDLE TO WOT, THE METER SCALES OR CHANGES RANGES AUTOMATICALLY. THERE MAY BE AN ERRONEOUS METER DISPLAY UNTIL THE VOLTMETER HAS LOCKED TO THE APPROPRIATE VOLTAGE READING. THE ERRONEOUS METER DISPLAY DOES NOT REPRESENT A DEFECTIVE TPS.
NOTE: IT IS RECOMMENDED THAT THE "RANGE LOCK" FEATURE ON MANY METERS BE SET FOR CHECKING TPS VOLTAGE.
Use the 0.00 range to measure TPS voltage.
If your voltmeter does not change ranges automatically and the meter is set to millivolt scale when reading full range voltages, the meter display may not indicate a valid value. This can be misinterpreted as an open circuit or suspect TPS. Ensure the meter is set to volts for measuring full range voltage levels.
327 EVP circuit below minimum voltage
EVP = testing/descrption etc.
DIAGNOSTIC TROUBLE CODE (DTC) 32/328: CHECK EVP SENSOR AND EGR VALVE OPERATION
DTC 32/328 in Key On Engine Off (KOEO) and Key On Engine Running (KOER) indicates that the EGR valve and/or EVP sensor voltage is lower than normal in the closed position. The EVP voltage is less than the closed limit voltage of 0.24 volts. Because of the preload of the EVP sensor it is very difficult to determine whether the EGR valve has malfunctioned or the EVP sensor has an abnormally high resistance.
Possible causes:
-- Poor continuity in EVP sensor harness or connectors.
-- Damaged EGR valve.
-- Damaged EVP sensor.
-- Damaged Powertrain Control Module (PCM).
l Key off.
l Disconnect EVP sensor.
l Inspect the connectors at harness and sensor for damaged pins, corrosion, loose wires, etc. Service as necessary.
l Remove vacuum line from EGR valve.
l Exercise EGR valve by applying and releasing vacuum with a vacuum pump.
l Reconnect vacuum line to EGR valve and electrical connector to EVP sensor.
l Rerun Key On Engine Off (KOEO) and Key On Engine Running (KOER) Self-Test.
More id 328 comes up again; but need to go to a service manual or disc
also some Testing by Tomco
