P1782
TRACTION CONTROL INPUT ELECTRICAL - P1782The traction control input allows the ABS/TCCM, which performs the traction control function to inform the TCM when traction control is in operation. This allows the TCM to select a specific shift pattern which increases the effectiveness of the traction control.
The signal has two states; active and inactive. In the inactive state the line is pulled high by a 1k21 resistor in the TCM and should rest at battery voltage. In the active state, the ABS/TCCM drives a square wave signal at 2.5 Hz i.e. ON for 200 ms, OFF for 200 ms. During the OFF phase the voltage should be greater than battery voltage minus 1.5 V and during the ON phase the voltage should be less than 1 V.
Because traction control is not fitted to all vehicles the traction control input will be open circuit on some cars. Diagnostics are limited to detection of permanent short circuit to ground. Fault detection is triggered if the signal line voltage is less than 1.8 V for longer than 200 ms. If a fault is detected code P1782 is stored and the traction control shift pattern is inhibited. The diagnostic test is performed continuously during initialization and operation.
Possible Causes:
Faulty harness wiring/connector.
Faulty signal from ABS CM.
Effects:
Traction control shift pattern disabled
Remedy:
Repair or renew harness / connection
Examine ABS/TCCM fault diagnosis.
Troubleshooting Schematic
Key To Schematic Diagrams
1. Transmission Control Module (TCM)
2. Transmission Unit
3. TCM Multi-pin Connector
4. Transmission Rotary Switch
5. Transmission Connector Plug
6. Engine Control Module
7. Instrument Pack
8. ABS/Traction Control Control Module
9. Kickdown Switch
Pin Outs