P0723

Circuit Description
Output speed information is provided to the PCM by the OSS, which is a permanent magnet (PM) generator. The PM generator produces a pulsing AC voltage. The AC voltage level and number of pulses increases as the speed of the vehicle increases. The PCM then converts the pulsing voltage to output speed, which is used for calculations. The vehicle speed can be displayed with a scan tool.
This DTC detects a low output speed when there is a high engine speed in a drive gear range. This is a type "B" DTC.

Conditions For Setting The DTC
In Park or Neutral:
- Transmission output speed change is greater than 10000 rpm.
- Conditions met for 6 seconds.
- Engine running time is greater than 2 seconds. Not in Park or Neutral:
- Transmission output speed change is greater than 512 rpm.
- Conditions met for 0.075 seconds
- Engine running time is greater than 2 seconds.
- Engine vacuum is less than 70 kPa.
- Output speed is greater than 1380 rpm for 1 second.
- NORAW-NOLAST < 60 rpm for 6 seconds.
- NORAW: Latest raw data of output shaft speed.
- NOLAST: Filtered previous data of output speed.

Action Taken When The DTC Sets
- Fixed to 4th gear.
- Maximum line pressure.
- Inhibit TCC engagement.
- The PCM will illuminate the Malfunction Indicator Lamp (MIL) and CHECK TRANS Lamp.

Conditions For Clearing The MIL/DTC
- The PCM will turn off the MIL and CHECK TRANS Lamp after three consecutive ignition cycles without a failure reported.
- The DTC can be cleared from the PCM history by using a scan tool.
- The DTC will be cleared from history when the vehicle has achieved 40 warmup cycles without a failure reported.
- The PCM will cancel the DTC default actions when the fault no longer exists and the ignition is cycled "off' long enough to power down the PCM.

Diagnostic Aids
- A 055 DTC P0723 will set when output speed has been detected and is lost.
- Inspect the wiring for poor electrical connection at the PCM. Look for possible bent, backed out, deformed or damaged terminals. Check for weak terminal tension as well. Also check for a chafed wire that could short to bare metal or other wiring. Inspect for a broken wire inside the insulation.
- When diagnosing for a possible intermittent short or open condition, move the wiring harness while observing test equipment for a change.

Test Description
The numbers below refer to the step numbers on the diagnostic chart:
5. This test checks the OSS circuit.
6. This test checks the integrity of the OSS.
8. This test checks the 5-volt and ground circuit of the PCM.








DTC P0723 Transmission output speed Sensor (OSS) Intermittent