Component Testing
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 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 probes J 35616-65, 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 |
|---|---|---|
| 2WD HI | 1475-1550 ohms | 1515 ohms |
| AWD/4WD Auto | 110-175 ohms | 140 ohms |
| 4WD HI | 625-700 ohms | 665 ohms |
| 4WD LO | 2300-2400 ohms | 2345 ohms |
| Neutral | 1000-1050 ohms | 1020 ohms |
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 | |||
| 2WD HI | 4.9-5.0 V | 1.80-2.18 V | 1.97 V | 37° |
| AWD/4WD Auto | 4.9-5.0 V | 4.10-4.59 V | 4.38 V | 102° |
| 4WD HI | 4.9-5.0 V | 2.78-3.22 V | 3.00 V | 124° |
| 4WD LO | 4.9-5.0 V | 1.33-1.67 V | 1.50 V | -76° |
| Neutral | 4.9-5.0 V | 2.27-2.68 V | 2.47 V | 0° |