Circuit Description
With the engine running and the transmission in Drive 4, the Sport Mode Indicator Lamp should transition from On to Off or from Off to On with each press of the Sport Mode Selector Switch. The ignition voltage is supplied directly to the indicator bulb. The transmission control module (TCM) controls the lamp by grounding the control circuit via an internal solid state device called a driver. The Sport Mode Selector Switch signal circuit is pulled up to B+ within the TCM. The other side of the switch connects to ground. When the switch is on, the signal voltage is pulled low. The TCM interprets this as sport mode requested. The Sport Mode selection causes the TCM to use a more aggressive shift schedule for improving performance and providing a more positive shift feel.
Diagnostic Aids
An intermittent may be caused by the following.
| • | Corrosion |
| • | Rubbed through wire insulation |
| • | Broken wire inside the insulation |
Refer to Symptoms in Engine Controls for Intermittents.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Transmission OBD Diagnostic System Check? | -- | ||||||||
2 | Any DTCs that are set must be corrected before performing this diagnostic procedure. Are there any DTCs set? | -- | Go to the applicable DTCs | |||||||
3 |
Does the Sport Mode indicator lamp turn ON and OFF? | -- | System OK | |||||||
4 |
Does the display change back and forth between ON and OFF? | -- | ||||||||
5 | Use the Scan Tool in order to command the Sport Mode indicator lamp ON and OFF. Does the lamp go ON and OFF? | -- | ||||||||
6 | Is the lamp always ON? | -- | ||||||||
Do the other indicator lamps in the instrument panel operate? | -- | |||||||||
8 |
Does the test lamp illuminate? | -- | ||||||||
9 | Check the Sport Mode Indicator Lamp circuit for the following conditions:
Refer to General Electrical Diagnosis in Wiring Systems. Is the action complete? | -- | -- | |||||||
10 |
Does the lamp illuminate? | -- | ||||||||
11 | Does the display always indicate ON? | -- | ||||||||
12 |
Does the state change each time the jumper is momentarily connected? | -- | ||||||||
13 |
Is the continuity indicated? | -- | ||||||||
14 | Use a fused jumper wire in order to connect the Sport Mode selector switch signal circuit terminal 2 to ground in the switch harness connector, while observing the Scan Tool . Does the display indicate ON? | -- | ||||||||
15 |
Is the resistance within the specified range? | 0-5ohms | ||||||||
16 | Repair the short to ground in the lamp control circuit. Did you complete the repair? | -- | -- | |||||||
17 | Repair the feed circuit to the instrument panel indicator lamps. Did you complete the repair? | -- | -- | |||||||
18 | Repair the signal circuit shorted to ground. Did you complete the repair? | -- | -- | |||||||
19 | Repair the open/high resistance signal circuit. Did you complete the repair? | -- | -- | |||||||
20 | Check the ground circuit to the Sport Mode switch for an open or a high resistance condition. Did you find and correct the condition? | -- | ||||||||
21 | Replace the Sport Mode switch. Did you complete the replacement? | -- | -- | |||||||
22 | Check the TCM harness connector for a poor connection or poor terminal tension. Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct the condition? | -- | ||||||||
23 | Replace the TCM. Refer to Transmission Control Module Replacement . Did you complete the replacement? | -- | -- | |||||||
24 |
Caution: Apply the parking brake and block the drive wheels before performing this procedure in order to prevent bodily injury. Does the Sport Mode lamp correspond to the operation of the switch? | -- | System OK |
