Component Testing
WARNING: This page is about a different car, the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
TCSCS - Mode Switch Circuit
- Key OFF. Remove the TCSCS.
- Using the L-BU probe J 35616-65B, measure the resistance for each of the mode positions of the TCSCS between the 5-volt reference circuit, TCSCS X1 pin 11, and the switch signal circuit TCSCS X1 pin 12.
- If the resistance is outside the specified ranges, replace the TCSCS.
- Test the TCCM for proper operation.
| Mode | Range | Nominal |
|---|---|---|
| 2 Hi | 1475-1550 Ω | 1515 Ω |
| 4WD Auto | 110-175 Ω | 140 Ω |
| 4 High | 625-700 Ω | 665 Ω |
TCCM - Mode Switch Circuit
- Key ON, engine OFF. Install the TCSCS.
- Using the Data Display feature of the scan tool, monitor the Mode Switch Supply and Return Voltages while turning the TCSCS through each mode.
- If the voltage is less than the specified value, test the affected circuit for an open/high resistance, short to ground or short together. If all circuits and connections test normal, reprogram the TCCM. If the DTC resets replace the TCCM.
- If the voltage is greater than the specified value, test the affected circuit for a short to voltage. If all circuits and connections test normal, reprogram the TCCM. If the DTC resets replace the TCCM.
- Perform the Circuit/System Testing.
| Mode | Mode Switch Supply Voltage | Mode Switch Return Voltage | Rotational Position Sensor | |
|---|---|---|---|---|
| Range | Nominal | |||
| 2 Hi | 4.9-5.0 V | 1.80-2.18 V | 1.97 V | 37° |
| 4WD Auto | 4.9-5.0 V | 4.10-4.59 V | 4.38 V | 102° |
| 4 Hi | 4.9-5.0 V | 2.78-3.22 V | 3.00 V | 124° |