P0736

AF23-5 AUTOMATIC TRANSAXLE

DTC P0736

Test 1-9:

Test 10-18:

Test 19-20:

Circuit Description with AF23-5 Automatic Transaxle
The TCM calculates gear ratio based on data from the automatic transmission input shaft speed and output shaft speed sensors. The TCM compares the known transmission gear ratio to a calculated ratio for each commanded gear.

If the TCM detects an incorrect reverse gear ratio, indicating excessive slip or drag within the transmission, then DTC P0736 sets. DTC P0736 is a type A DTC.

Conditions for Running the DTC
^ No TR switch DTC P0705.
^ No TFT DTCs P0711, P0712, or P0713.
^ No ISS DTC P0717.
^ No OSS DTC P0722.
^ No engine speed DTC P0727. No TCC DTC P0741.
^ No solenoid DTCs P0962, P0963, P0966, P0967, P0970, P0971, P0973, P0974, P0976, P0977, P0979, P0980, P0982, P0985 or P0986.
^ No engine torque DTC P1781. No throttle position DTC P1791.
^ The ignition voltage is 10.5-18 volts.
^ The engine run time is 5 seconds or greater.
^ The transmission temperature is 20°C (68°F) or greater.
^ The transmission is not in PARK or NEUTRAL.
^ The elapsed time since the most recent range change is 8 seconds or greater,
^ The engine torque is 55 - 350 Nm (41 - 258 ft. lbs.).
^ The throttle position (TP) is 10 percent or greater.
^ The output shaft speed (OSS) is 500 RPM or greater after shifting into reverse.

Conditions for Setting the DTC
The TCM commands reverse and the actual gear ratio is not within 2.50:1-3.75:1 for 6 seconds.

Action Taken When the DTC Sets
^ The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
^ The TCM turns the Trans. Protection Mode ON. When the Trans. Protection Mode is ON, the following conditions occur:
- The transmission will operate in 5th gear when the transmission is shifted into D or I range and 2nd gear when shifted into L range.
- The line pressure is at maximum.
- The torque converter clutch (TCC) is disabled.
- The TCM freezes the transmission adaptive functions.
^ The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Record.
^ The TCM stores DTC P0736 in TCM history.

Conditions for Clearing the MIL/DTC
^ The ECM turns off the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
^ The TCM clears the MIL when the condition no longer exists.
^ A scan tool can clear the DTC.
^ The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
^ The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

Diagnostic Aids
Ask the customer about overloading the vehicle, exceeding the trailer towing limit, or towing in DRIVE (D).

Test Description
The numbers refer to the step numbers on the diagnostic table.
5. This step determines that shift solenoid 4 or the U1 shift valve is stuck if the TCC applies in 2nd gear and stalls the engine.
6. This step determines if the output shaft speed sensor signal is skewed by a large factor.
7. This step determines if the input shaft speed sensor signal is skewed by a large factor.