P039

DTC PO39: Part 1 Of 2:

DTC PO39: Part 2 Of 2:

TCC Circuit:

CIRCUIT DESCRIPTION
The Torque Converter Clutch (TCC) solenoid controls the hydraulic fluid for apply or release. The diagnostic test checks for a torque converter clutch not engaged or slipping condition by monitoring the slip speed. Slip speed is the difference between engine speed and transaxle turbine speed. When the TCC is applied, the engine is coupled directly to the transaxle through the TCC. Almost no slippage should occur, so the slip speed is nearly 0. If rpm is too high at a given speed, the Powertrain Control Module (PCM) diagnosis the condition as the TCC slipping or not engaged and Code P039 is set.

TEST CONDITIONS
1. Codes P024, P026, P027, P028, P031, P032, P034, P056 and P075 not set.
2. Transaxle in 3rd or 4th gear.
3. Engine running.
4. TCC commanded "ON" (100%).
5. Transaxle not in park or neutral.
6. Throttle position switch open.
7. Delivered torque from engine not 32 ft lb or less (coast down condition).
8. Delivered torque from engine not 508 ft lb or more (engine under extreme load (Example: towing a trailer or wide open throttle).

TCC Slipage Vs. Engine Torque:

FAILURE CONDITIONS
3.71 Final Drive (VIN 9) - Slip speed 48 rpm or greater for 4.5 seconds.
3.11 Final Drive (VIN Y) - Slip speed greater than acceptable value based on engine torque delivered for 4.5 seconds. Refer to chart in accompanying image for acceptable TCC slip values.

ACTION TAKEN
1. PCM turns "ON" the Malfunction Indicator Lamp (MIL) (Service Engine Soon).
2. TCC is disabled for the entire ignition cycle.

NOTES ON FAULT TREE
(Part 1 of 2)
1. Testing Torque Management Brake Switch input to the PCM PI71. If test passes, the display will change from HI 0 to HI X. If test fails, the display will not change.
2. Checking for an open in CKT 420 between C129 and C101.

(Part 2 of 2)
3. Checking for open or shorts inside the transaxle. The resistance should be between 10 and 40 ohms.
4. Checking if CKT 422 is open or if the PCM is unable to control the output.
5. Checking PCM's ability to control the TCC output.
6. Checking if TCC is operating correctly by checking amount of TCC slip when clutch is engaged.


NOTES ON INTERMITTENTS
Intermittent code P039 setting may be caused by delayed TCC engagement (usually the first apply after a cold start) or by TCC slippage during high engine load conditions. Delayed TCC engagement can be checked using PCM 0utput Override PS01 (TCC Solenoid) to disengage and engage TCC and time how long it takes TCC to engage by watching PCM Data PD73 (Torque Converter Slip Speed). Delays of over 5 seconds may cause the code to set. TCC slippage during high load conditions can be determined by looking at code P039 Snapshot Data. High throttle angle (PD01), MAP (PD02), and engine coolant temperatures (PD04) may indica!e a high load condition. Duplicating the high load conditions may cause the code setting conditions to occur.