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Home >> Cadillac >> 2004 >> CTS Base, 3.2 N >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 28 (Automatic Transmission - 5L40-E (DTC P0115 To P0742)) >> Automatic Transaxle Diagnosis >> DTC P0723 >> Test Description

Test Description

WARNING: This page is about a different variant/trim than selected.

The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  The resistance measurement will not change if either the OSS high signal circuit or the OSS low signal circuit, but not both, is shorted to ground. The vehicle speed detector in the TCM and the OSS are matched in such a way that an open or a short to ground in the OSS low signal circuit will not usually cause a loss of speed signal or a DTC P0723 to set.
  2. 6:  This step isolates the short between the OSS and the wiring.
  3. 8:  The DMM will detect AC voltage if the OSS high signal circuit is shorted to ground.
  4. 11:  Refer to the latest procedures for TCM reprogramming.
DTC P0723

Step Action Value(s) Yes No
1 Did you perform the Diagnostic System Check - Automatic Transmission? - Go to Step 2  Go to Diagnostic System Check - Automatic Transmission
2
NOTE: In order to avoid damage to the drive axles, support the lower control arms in the normal horizontal position. Do not run the vehicle in gear with the wheels hanging down at full travel.
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
    3. IMPORTANT:
    • Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM.
    • Using the Clear Info function erases stored DTCs in both the ECM and TCM.
  3. Record the DTC Freeze Frame and Failure Records.
  4. Clear the DTC.
  5. Raise the drive wheels.
  6. Support the lower control arms so that the drive axles are in a horizontal, straight, position.
  7. Start the engine.
  8. Shift the transmission into D5.
  9. Select Transmission OSS on the scan tool.
Does the scan tool display transmission output speed above the specified value?		 100 RPM Go to Intermittent Conditions in Engine Controls - 2.6L and 3.2L or Intermittent Conditions in Engine Controls - 3.6L (LY7) Go to Step 3 
3 
  1. Turn OFF the ignition.
  2. Disconnect the TCM.
  3. Measure the resistance between the OSS high signal and the OSS low signal circuits at the TCM connector.
Is the resistance within the specified range?		 325-575 ohm Go to Step 5  Go to Step 4 
4 Test the OSS high signal circuit and the OSS low signal circuit for the following conditions:
  • An open circuit or high resistance condition
  • OSS high signal and OSS low signal circuits shorted together

Refer to Testing for Continuity in Wiring Systems.
Did you find and correct a condition?		 - Go to Step 12  Go to Step 9 
5 Measure the resistance between the OSS high signal circuit at the TCM connector and ground.
Is the resistance greater than the specified value?		 50K ohm Go to Step 8  Go to Step 6 
6 
  1. Leave the DMM connected between the OSS high signal circuit and ground.
  2. Disconnect the OSS.
  3. Measure the resistance.
Is the resistance greater than the specified value?		 50K ohm Go to Step 9  Go to Step 7 
7 Repair the short to ground in the OSS high signal circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 - Go to Step 12  -
8 
  1. Connect the DMM between the OSS high signal and the OSS low signal circuits at the TCM connector.
  2. Measure the AC voltage with the DMM while rotating the drive wheels by hand.
Is the AC voltage equal to or greater than the specified value?		 0.5 V Go to Step 11  Go to Step 9 
9
  1. Remove the OSS. Refer to Output Speed Sensor Replacement .
  2. Inspect the OSS and the OSS rotor for the following conditions:
    • OSS damage
    • OSS rotor damage
    • Excessive air gap between the OSS rotor and the OSS
    • Incorrect alignment between the OSS and the OSS rotor
    • Damaged or missing OSS sensor spacer
  3. Repair or replace any of the above items as necessary.
Did you find and correct a condition?		 - Go to Step 12  Go to Step 10 
10 Replace the OSS. Refer to Output Speed Sensor Replacement .
Did you complete the repair?		 - Go to Step 12  -
11  Replace the TCM. Refer to Transmission Control Module (TCM) Replacement .
Is the action complete?		 - Go to Step 12  -
12 Perform the following procedure in order to verify the repair:
  1. Select DTC.
  2. Select Clear Info.
  3. Drive the vehicle in D5 and observe Transmission OSS on the scan tool.
  4. Ensure the Transmission OSS is greater than 750 RPM and does not drop more than 650 RPM for at least 2 seconds.
  5. Select Specific DTC.
  6. Enter DTC P0723.

Has the test run and passed?		 - Go to Step 13  Go to Step 2 
13 With the scan tool, observe the stored information, capture info and DTC info.
Does the scan tool display any DTCs that you have not diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 2.6L and 3.2L or Diagnostic Trouble Code (DTC) List in Engine Controls - 3.6L (LY7) System OK
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