Corsica V6-191 3.1L (1990)
Chart C-8 Wiring Diagram
CIRCUIT DESCRIPTION:
The 2nd gear switch in this vehicle is open in 2nd and 3rd gear. The ECM uses this signal to disengage the TCC when going into a downshift.
The 3rd gear switch will open in 3rd gear.
TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.
1.
Some "Scan" tools display the state of these switches in different ways. Be familiar with the type of tool being used. Since both switches should be
in the closed state during this test, the tool should read the same for either the 2nd or 3rd gear switch.
2.
Determines whether the switch or signal circuit is open. The circuit can be checked for an open by measuring the voltage (with a voltmeter) at the
TCC connector. Should be about 12 volts.
3.
Because the switch(s) should be grounded in this step, disconnecting the TCC connector should cause the "Scan" switch state to change.
4.
This switch state should change when the vehicle shifts into 2nd gear.
DIAGNOSTIC AIDS:
If vehicle is road tested because of a TCC related problem, be sure the switch states do not change while in 4th gear because the TCC will disengage. If
switches change state, carefully check wire routing and connections.
