Theory Of Operation

WARNING: This page is about a different variant/trim than selected.

The paddle switches allows the operator to select when the transmission will upshift or downshift when the system is activated. This is done by using the paddle switches mounted to the steering wheel. The TCM supplies a signal voltage and a return circuit to the paddle switches. The Up (+) and Down (-) buttons are sensed due to each switch having resistance of different values between the signal and return side of the circuit. The TCM monitors the voltage of the signal circuit to determine what the operator is requesting when a button is pressed.

The table below shows the expected voltages detected by the TCM for the various switch states. The Short to Ground, open Circuit and Short to Battery voltages are the thresholds used for fault detection. The TCM supplies a 5.0 volt signal to both switches, as well as a return circuit. The signal passes through a 24.3 k ohm resistor in each switch when the switches are not pressed. When the Right Switch (+) is pressed, the signal passes through a 1.2 k ohm resistor and when the Left Switch (-) is pressed the signal passes through a 2.0 k ohm resistor. The TCM monitors the voltage of the signal circuit to process switch requests or determine if a fault is present.

STATE	Minimum Volt	Maximum Volt
Short to Ground	0.0	0.239
Both Switches (+ and -) Pressed	1.115	1.528
Right Switch (+) Pressed	1.533	1.938
Left Switch (-) pressed	2.134	2.622
Both Switches (+ and -) Released	4.040	4.527
Open Circuit	4.769	4.999
Short to Battery	5.0	65.0

The table below shows typical expected resistance of the Paddle Switches in the state indicated when measured with a DVOM. All measurement made from the signal and return circuits.

State	Typical resistance
Both Switches (+ and -) Released	10.944 k Ω - 13.376 k Ω *
Right Switch (+) Pressed	0.986 k Ω - 1.205 k Ω *
Left Switch (-) Pressed	1.644 k Ω - 2.01 k Ω *
Both Switches (+ and -) Pressed	0.653 k Ω - 0.799 k Ω *
Right Switch (+) Released, Left Switch (-) Open Circuit	21.879 k Ω - 26.741 k Ω *
Right Switch (+) Pressed, Left Switch (-) Open Circuit	1.032 k Ω - 1.262 k Ω *
Left Switch Released, Right Switch (+) Open Circuit	21.906 k - 26.774 k Ω *
Left Switch Pressed, Right Switch (+) Open Circuit	1.778 k - 2.173 k Ω *
Right Switch (+) Released	21.870 k Ω - 26.730 k Ω **
Right Switch (+) Pressed	1.080 k Ω - 1.320 k Ω **
Left Switch (-) Released	21.870 k Ω - 26.730 k Ω **
Left Switch (-) Pressed	1.800 k Ω - 2.200 k Ω **

NOTE:

* Measured at steering wheel side of Steering Column Control Module (SCCM) harness connector.

NOTE:

** Measured at switch, switches disconnected from vehicle.