4L60-E / 4L65-E Automatic Transmission

DTC P0894





Circuit Description with 4L60-E / 4L65-E Automatic Transmission
The powertrain control module (PCM) monitors the difference between engine speed and transmission output speed. In D3 drive range with the torque converter clutch (TCC) engaged, the engine speed should closely match the transmission output speed. In D4 drive range, with the TCC engaged, the TCC slip speed should be -20 to +50 RPM.

When the PCM detects excessive TCC slip when the TCC should be engaged, then DTC P0894 sets. DTC P0894 is a type B DTC.

DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0894 Transmission Component Slipping

Conditions for Running the DTC
^ No TP sensor DTCs P0122 or P0123.
^ No VSS DTCs P0502 or P0503.
^ No TCC solenoid valve DTC P0740.
^ No 1-2 SS valve DTC P0753.
^ No 2-3 SS valve DTC P0758.
^ No 3-2 SS valve DTC P0785.
^ No TFP manual valve position switch DTC P1810.
^ No TCC PWM solenoid valve DTC P2761.
^ The engine speed is greater than 450 RPM for 5 seconds.
^ The engine is not in fuel cutoff.
^ The engine torque is 67 - 542 Nm (50 - 400 ft. lbs.).
^ The engine vacuum is 0-105 kPa (0-15 psi).
^ The TP angle is 20-99 percent.
^ The vehicle speed is 48-131 km/h (30-82 mph).
^ The engine speed is 1,500-3,000 RPM.
^ The speed ratio is 0.69-0.88, speed ratio is engine speed divided by the transmission output speed.
^ The gear range is D4.
^ The commanded gear is not 1st gear.
^ The TFT is 20-150°C (68-302°F).
^ The shift solenoid performance diagnostic counters are zero.

Conditions for Setting the DTC
DTC P0894 sets if the following conditions occur for three TCC cycles.
^ The TCC is commanded ON for 5 seconds.
^ The TCC is at 40 percent duty cycle for 5 seconds.
^ The TCC slip speed is 130-800 RPM for 7 seconds.

^ Important:
The following actions may occur before the DTC sets.

If the TCC is commanded ON for 5 seconds, the TCC is at 40 percent duty cycle for 5 seconds, the TP angle is 20-99 percent and the transmission slip counter has incremented to either 1 or 2, out of 3 to increment the fail counter for the current ignition cycle, then the following slip conditions and actions may increment the fail counter for the current ignition cycle:These conditions must occur sequentially.

Condition 1
If the TCC slip speed is 130-800 RPM for 7 seconds, then the PCM will command maximum line pressure and freeze shift adapts from being updated.

Condition 2
If Condition 1 is met and the TCC slip speed is 130-800 RPM for 7 seconds, then the PCM will command the TCC Off for 1.5 seconds.

Condition 3
If Condition 2 is met and the TCC slip speed is 130-800 RPM for 7 seconds, then the fail counter on the current ignition cycle is incremented.
The above slip conditions and actions may be disregarded if the TCC is commanded OFF at any time as a result of a driving maneuver, sudden acceleration or deceleration.

Action Taken When the DTC Sets
^ The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
^ The PCM commands maximum line pressure.
^ The PCM inhibits TCC engagement.
^ The PCM inhibits 4th gear if the transmission is in hot mode.
^ The PCM freezes shift adapts from being updated.
^ The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
^ The PCM stores DTC P0894 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
^ The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
^ A scan tool can clear the MIL/DTC.
^ The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
^ Bronze material found in the transmission oil pan may indicate stator shaft bushing wear. If bushing wear is suspected, inspect the stator shaft and the input, turbine, shaft for damage.
^ Refer to Symptoms - Automatic Transmission. Symptom Related Diagnostic Procedures

Test Description














The numbers below refer to the step numbers on the diagnostic table.
3. This step tests the torque converter for slippage while in a commanded lock-up state.