Second Gear Start Switch/Indicator Always On or Inoperative 3.8L VIN K Only
Circuit Description
The 2nd gear start switch enables the operator to select a 2nd gear start for increased traction in slippery driving conditions. When the operator selects 2nd gear, the second gear start switch input signal momentarily toggles to zero volts. The PCM then turns ON the 2nd gear start mode indicator lamp and de-energizes the 1-2 shift solenoid, enabling second gear. This 2nd gear start mode indicator lamp is located within the 2nd gear start switch.
During light and medium acceleration conditions, the vehicle starts in 2nd gear when second gear is selected. However, 2nd gear starts are overridden and 1st gear starts occur if a hard acceleration condition (wide open throttle) is requested. Normal 1st gear start mode is obtained by toggling the 2nd gear start switch again, or when the ignition switch is cycled OFF then ON.
Diagnostic Aids
If the electrical circuit checks are OK and 2nd gear starts are not correct, then a mechanical/hydraulic malfunction might exist. Refer to Automatic Transmission Diagnosis, Section 7.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests the second gear start switch circuits.
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This step tests for a faulty 2nd gear start switch.
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This step tests for a voltage input from the PCM to the 2nd gear start switch.
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This step tests for a voltage input from the fuse to the 2nd gear start switch.
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This step tests for a faulty indicator lamp circuit within the 2nd gear start switch.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Is ON displayed the first time you press the switch, and OFF when you press the switch a second time? | -- | |||
Install a J 36169-A Fused Jumper Wire between terminals E and F of the 2nd gear start switch. Observe the scan tool display. Does the scan tool indicate On? | -- | |||
3 |
Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | -- | ||
Using the J 39200 DMM and the J 35616-A Connector Test Adapter Kit, measure the voltage input at terminal E of the 2nd gear start switch. Did you measure the voltage? | -- | |||
5 | Inspect circuit 1571 (BRN/WHT) for an open. Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | -- | ||
Connect a test lamp to ground and probe terminal A of the 2nd gear start switch. Is the test lamp On? | -- | |||
7 |
Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | -- | -- | |
Important: Connect the positive meter lead to terminal A and the negative meter lead to terminal B. Did you measure the continuity? | -- | |||
9 | Inspect circuit 1572 (PPL/WHT) for an open. Refer to Electrical Diagnosis, Section 8. Did you find and correct a problem? | -- | -- | |
10 | Replace the 2nd gear start switch. Refer to Instrument Panel, Gauges and Console, Section 8. | -- | ||
11 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete? | -- | -- | |
12 | After the repair is complete, select 2nd Gear Start Lamp on the scan tool. Does the scan tool display On when you first press the 2nd gear start switch, and then Off when you press the 2nd gear start switch a second time, and does the 2nd gear start switch indicator lamp turn On after you first press the second gear start switch, and then turn Off after you press the 2nd gear start switch a second time? | -- | System OK |
