GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2003 🢒 L300/LW300 🢒 Engine 🢒 Engine Controls - 3.0L (L81) 🢒 DTC P1868

DTC P1868 3.0L (L81)

Circuit Description

Transmission fluid life is determined by monitoring transmission fluid temperature over a period of time. The TCM calculates transmission fluid life based on a set of temperature ranges stored in TCM memory. As the vehicle is driven, a counter increments. The rate at which the counter increments depends on the temperature range in which the transmission is currently operating in. The higher the temperature range, the faster the counter increments. As the counts increment, the TCM will begin to decrease the fluid life percentage from 100, high fluid life, to 0, low fluid life.

If the TCM detects a calculated transmission oil life of 10 percent or less, then DTC P1868 sets. DTC P1868 is a type C DTC.

Conditions for Running the DTC

No TFT DTCs P0711, P0712, or P0713.

Conditions for Setting the DTC

The calculated transmission oil life remaining is 10 percent or less.

Action Taken When the DTC Sets
    • The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
    • The TCM requests the ECM to illuminate the service vehicle soon (SVS) lamp.
    • The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
    • The TCM stores DTC P1868 in TCM history.

Conditions for Clearing the SVS Lamp/DTC
    • The TCM clears the SVS lamp request when the condition no longer exists.
    • A scan tool can clear the SVS Lamp/DTC.
    • The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
    • The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

Diagnostic Aids

Inspect the transmission cooling system for possible blockage and restrictions.

Test Description

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

  1. This step changes the AT fluid and filter. It is important to reset the oil life monitor after the fluid and filter are replaced.

DTC P1868

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check - Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls in Engine Controls - 3.0L (L81)

2

  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 Failure Records. Using the Clear Info function erases the Failure Records from the TCM.

  3. Record the DTC Failure Records.
  4. Clear the DTC.
  5. Change the AT fluid and filter.

    6. Refer to Automatic Transmission Fluid Filter and Seal Replacement

  6. Inspect the AT fluid for correct level.
  7. Add new fluid as necessary.
  8. Use the scan tool in order to reset the transmission oil life monitor to 100%.

Did you complete the above procedures?

--

Go to Step 3

--

3

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Ensure that the transmission oil life monitor displays 100%.
  4. Select Specific DTC.
  5. Enter DTC P1868.

Has the test run and passed?

--

Go to Step 4

Go to Step 2

4

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 - 3.0L (L81)

System OK