• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
ISS Low Signal | -- | P0716, P0717 | -- | P0716 |
ISS High Signal | P0716, P0717 | P0716, P0717 | P0716, P0717 | P0716 |
The automatic transmission ISS is a permanent magnet. The ISS mounts in the case cover facing the reluctor wheel of the input shaft. As the reluctor wheel is driven by the turbine shaft, an AC signal is induced in the ISS. Higher vehicle speeds induce a higher frequency and voltage at the sensor. There is a fixed air gap between the sensor and the teeth on the sensor reluctor wheel. The ISS input is used by the transmission control module (TCM) in order to control line pressure, torque converter clutch (TCC) apply and release, and transmission shift patterns. This sensor is also used to calculate the appropriate gear ratios and TCC slippage. This diagnostic indicates stuck, erratic, or intermittent conditions in the system.
• | DTC P0121, P0122, P0123, P0717, P0722, P0723, P0757, P0973, or P0974 is not set. |
• | The ignition voltage is between 8 and 18-volts. |
• | The engine speed is between 500 and 6,500 RPM for 5 seconds. |
• | The throttle position (TP) sensor is 8 percent or greater. |
• | The vehicle speed is 16 km/h (10 mph) or greater. |
• | The transmission input shaft speed is 1,050 RPM or greater for 2 seconds. |
• | The transmission input shaft speed has not changed by 1,000 RPM or less for 2 seconds. |
• | The engine torque is between 50-1 492 N·m (37-1,100 lb ft). |
• | DTC P0722 or P0723 is not set. |
• | The ignition voltage is between 8 and 18-volts. |
• | The engine speed is between 500 and 6,500 RPM for 5 seconds. |
• | The vehicle speed is 16 km/h (10 mph) or greater. |
• | The engine torque is between 50-1 492 N·m (37-1,100 lb ft). |
The transmission input shaft speed drops by 1,000 RPM or greater for 3.25 seconds.
The transmission input shaft speed is less than 100 RPM for 4.5 seconds.
DTC P0716 and P0717 are type B DTCs.
DTC P0716 and P0717 are type B DTCs.
Automatic Transmission Controls Schematics
Transmission General Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | J 35616 GM Terminal Test Kit |
• | J 44152 Jumper Harness (20 Pins) |
⇒ | 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. |
⇒ | If less than the specified range, repair the short to ground. |
⇒ | If less than the specified range, repair the short to ground. |
⇒ | If all circuits test normal, test or replace the internal transmission wiring harness or the ISS. |
Perform the Diagnostic Repair Verification after completing the repair.
Vehicle Input Speed Sensor Replacement .
Control Module References for TCM replacement, setup, and programming.