Circuit/System Testing
WARNING: This page is about a different car, the 2011 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the TCM X1 connector.
- Measure for 820-1,428 ohms between the ISS high signal circuit terminal 3 and the ISS low signal circuit terminal 26.
- If greater than the specified range test the ISS high signal and the ISS low signal circuits for an open/high resistance. If the circuits/connections test normal, replace the input shaft speed sensor.
- If less than 820 ohms test the ISS high signal and the ISS low signal circuits for a shorted together condition. If the circuits/connections test normal, replace the input shaft speed sensor.
- Measure for more than 10 ohms of resistance between the ISS high signal circuit terminal 3 and ground.
- If less than the specified range, repair the short to ground.
- Measure for more than 10 ohms of resistance between the ISS low signal circuit terminal 26 and ground.
- If less than the specified range, repair the short to ground.
- Connect the TCM connector. Disconnect the transmission 20-way connector.
- Ignition ON, test the ISS high signal circuit terminal 3 for a short to voltage.
- If all circuits test normal, test or replace the internal transmission wiring harness or the ISS sensor.