Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
- Always inspect position sensor signal connectors for proper terminal contact.
- All diagnostic connections must be made with the approved test probes to prevent the creation of poor terminal contact.
- Disconnect the transmission X176 24-way connector.
- Connect the DT-48493 to the transmission X176 24-way connector. See Special Tools .
- Test the circuits in the Position Sensor Specification table as indicated below. Also test these circuits for short to ground.
- If any of the circuits are not within specification, test the internal transmission harness for the condition.
- If the internal transmission harness tests OK, replace the drive motor generator.
- Disconnect DT-48493 from the transmission X176 24-way connector. See Special Tools .
- Connect the DT-48493 jumper harness to the transmission X176 24-way connector at the vehicle harness. See Special Tools .
- Disconnect PIM connector X1.
- Test the circuits in the PIM to Transmission Terminal Reference table as indicated below. Also test these circuits for short to ground and the shield circuit if not presently grounded to the PIM assembly.
- If any of the circuits are not within the specified range, repair or replace the wiring harness.
- If all circuits test normal, replace the PIM.
IMPORTANT:
The drive motor generator position sensor circuits require proper circuit integrity for correct system operation. Just a few ohms of additional circuit resistance may cause position sensor signal degradation.
Position Sensor Specification
| Transmission X176 24-way Connector/Terminal | Transmission X176 24-way Connector/Terminal | Minimum Resistance | Maximum Resistance |
|---|---|---|---|
| Test at DT-48493 connected to transmission. See Special Tools . | |||
| 8 | 9 | 7.0 ohms | 9.0 ohms |
| 10 | 11 | 23 ohms | 26 ohms |
| 12 | 14 | 20 ohms | 23 ohms |
| 8 | 12 | Over 1 M ohm | - |
| 8 | 10 | Over 1 M ohm | - |
| 10 | 12 | Over 1 M ohm | - |
PIM to Transmission Terminal Reference
| Transmission X176 24-Way Connector/Terminal | PIM Connector X1/Terminal | Minimum Resistance | Maximum Resistance |
|---|---|---|---|
| Harness Continuity Test | |||
| 8 | 56 | - | less than 1 ohm |
| 9 | 55 | - | less than 1 ohm |
| 10 | 54 | - | less than 1 ohm |
| 11 | 53 | - | less than 1 ohm |
| 12 | 52 | - | less than 1 ohm |
| 14 | 51 | - | less than 1 ohm |