TT Terminal Circuit

TT TERMINAL CIRCUIT WIRING DIAGRAM

TT Terminal Circuit:

CHECKING TERMINAL TT OUTPUT VOLTAGE
The following items can be checked using a voltmeter connected to the TT terminal of DLC1.
^ Throttle Position Sensor signal
^ Brake signal
^ Shift position signal
1. Voltmeter connection

TT Terminal Location In DLC1:

- Connect the positive (+) probe of the voltmeter to terminal TT and the negative (-) probe to terminal E1 of the data link connector 1 (DLC1).
HINT:
Use a voltmeter with an internal resistance of at least 10 k Ohms. If a voltmeter with small internal resistance is used, the correct voltage will not be indicated.
2. Turn ignition switch to on (do not start the engine).
3. Check throttle position sensor signal.

Throttle Position Sensor Signal Test At TT Terminal Of DLC 1:

- Voltage should change from approximately 0 volts to approximately 8 volts in 1 volt steps, as the accelerator pedal is gradually depressed from the fully closed position.
4. Check brake signal (lock-up cut signal)
- Open the throttle valve fully to apply approximately 8 volts to terminal TT.
- In this condition, check terminal TT voltage when the brake pedal is depressed and released.

TT terminal voltage:
0 volts (When brake pedal is depressed)
8 volts (When brake pedal is released)
5. Start engine.
6. Check shift position signal (vehicle speed above 10 km/h or 6 mph)
- Check up-shifting together with terminal TT voltage.
HINT: Check for light shocks from up-shifting and for changes in the tachometer.


Gear Position Terminal TT
Output Voltage
1st Gear Below 0.5 V
2nd Gear 1.5 - 2.6 V
2nd Lock-up 2.5 - 3.6 V
3rd Gear 3.5 - 4.6 V
3rd Lock-up 4.5 - 5.8 V
0/D 5.5 - 6.6 V
O/D Lock-up 6.5 - 7.6 V
^ If terminal TT output voltage is not correct, inspect the harness between the engine control module (ECM) and the data link connector (DLC1).
^ If the harness checks OK, check and replace the ECM.