Part 2 of 2

DTC P039:

Brake Switch Circuit:

CIRCUIT DESCRIPTION:
The torque converter clutch solenoid controls the hydraulic fluid for TCC 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 rpm/speed ratio is nearly constant. If rpm is too high at a given speed, the PCM diagnosis the condition as the TCC slipping or not engaged and Code P039 is set.

NOTES ON FAULT TREE:
3. Checking for open or shorts inside the transaxle. The resistance should be between 10 and 40.
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 Output Override PS01 (TCC SOL) to disengage and engage TCC and time how long it takes TCC to engage by watching PCM Data PD73 (SLIP SPD). 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 indicate a high load condition. Duplicating the high load conditions may cause the code setting conditions to occur.