Diagnostic Instructions
DTC Descriptors
DTC P0716: Input Speed Sensor (ISS) Performance
DTC P0717: Input Speed Sensor (ISS) Circuit Low Voltage
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
ISS High Signal
| P0716, P0717
| P0716, P0717
| P0716, P0717
| P0716, P0717
|
ISS Low Signal
| --
| P0716, P0717
| --
| P0716, P0717
|
Typical Scan Tool Data
Transmission ISS
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
|
Operating Conditions:
Engine running in PARK, normal operating temperature
Parameter Normal Range:
500-800 RPM
|
Transmission ISS
| 0 RPM
| 0 RPM
| 0 RPM
|
Circuit/System Description
The automatic transmission ISS is a permanent magnet with a coil of wire wound around it. 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
input speed sensor. Higher vehicle speeds induce a higher frequency and a higher 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 powertrain control module (PCM)
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.
Conditions for Running the DTC
P0716
• | DTC P0717 has passed this ignition. |
• | No ISS DTC P0716 or P0717. |
• | No VSS DTC P0502 or P0503. |
• | No 1-2 shift solenoid valve DTC P0752. |
• | The engine speed is greater than 500 RPM for 5 seconds and not in fuel cut-off. |
• | The vehicle speed is 8 km/h (5 mph) or greater. |
• | The calc. throttle position is 14 percent or greater. |
P0717
• | No VSS DTC P0502 or P0503. |
• | The engine speed is greater than 500 RPM for 5 seconds and not in fuel cut-off. |
• | The vehicle speed is 8 km/h (5 mph) or greater. |
• | The engine torque is greater than 50 N·m (37 lb ft). |
Conditions for Setting the DTC
P0716
The input shaft speed changes by 1,300 RPM or greater for 0.8 second.
P0717
The input shaft speed is less than 100 RPM for 5 seconds.
Action Taken When the DTC Sets
• | DTC P0716 and P0717 are type B DTCs. |
• | The TCM commands maximum line pressure. |
• | The TCM freezes transmission adaptive functions. |
• | The TCM calculates input speed based on engine speed and gear ratio. |
Conditions for Clearing the DTC
DTC P0716 and P0717 are type B DTCs.
Diagnostic Aids
• | DTC P0716 detects a large change in the input speed signal in a very short period of time; an unrealistic change indicates an intermittent fault. |
• | DTC P0717 detects a very low input speed when the vehicle speed is greater than a calibrated value; this indicates a continuous fault. |
• | Inspect the ISS, wire harness, connector, and PCM for metallic debris, damage, or misalignment. Ensure the wiring harness is not stretched too tightly or other components are pressing on the automatic transmission inline 20-way connector body. Also
inspect for proper clearance to any other components and wiring. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
• | J 44257 Main Wiring Harness Connector Remover |
Circuit/System Verification
Start the engine in PARK and observe the transmission ISS on the scan tool while varying the engine speed. The transmission ISS should vary with the engine speed and not drop out.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, using the
J 44257 main wiring harness connector remover, disconnect the automatic transmission inline 20-way connector and install the
J 44152 jumper
harness on the transmission pass-thru connector.
- Using the light blue J 35616-65B test probe from the J 35616-D GM terminal test kit, test for between 820-1,428 ohms between the ISS high signal circuit, jumper harness pin S, and the ISS low signal
circuit, jumper harness pin V.
⇒ | If greater than the specified range, test the affected circuits for an open/high resistance. If both circuits test normal, replace the ISS. |
⇒ | If less than the specified range, test the affected circuits for a shorted together condition. If both circuits test normal, replace the ISS. |
- Test for greater than 10K ohms between the ISS high signal circuit, jumper harness pin S, and all other circuits of the
J 44152 jumper harness, except the ISS low signal circuit, jumper harness
pin V.
⇒ | If less than the specified range, the affected circuits are shorted together. Replace the transmission internal wire harness. |
- Test for greater than 250 ohms from the ISS high signal circuit, jumper harness pin S, and the ISS low signal circuit, jumper harness pin V, to the transmission case.
⇒ | If less than the specified value, test the affected circuits for a short to the transmission case. If both circuits test normal, replace the ISS. |
- Using the
J 44257 main wiring harness connector remover, remove the
J 44152 jumper harness from the transmission pass-thru connector and install it on the engine
side of the automatic transmission inline 20-way connector.
- Disconnect the X3 harness connector at the PCM.
Important: When probing a terminal for testing procedures, it is imperative to use the proper test probe from the J 35616-D GM terminal test kit. Prior versions of the J 35616 GM terminal test kit do not contain
the proper probes for testing TCM/ECM/PCM connectors. TCM/ECM/PCM harnesses use 0.64 mm (0.03 in) round terminals. The correct probe for this size terminal is the light blue J 35616-64B probe. ALL PREVIOUS J 35616-64
AND J 35616-64A PROBES SHOULD BE DISCARDED. The 1.00 mm (0.04 in) brown J 35616-6 probe is most widely mistaken for use with 0.64 mm (0.03 in) terminals. Use of the 1.00 mm (0.04 in) brown
probe in a 0.64 mm (0.03 in) terminal will deform the terminal, likely resulting in an intermittent open condition.
- Using the light blue J 35616-64B probes from the J 35616-D GM terminal test kit, test for greater than 250 ohms from the ISS high signal circuit, jumper harness terminal S, and the ISS low signal circuit, jumper
harness terminal V, to a good ground.
⇒ | If less than the specified value, test the affected circuit for a short to ground. |
- Using the light blue J 35616-64B probes, test for greater than 10K ohms between the ISS high signal circuit, jumper harness terminal S, and all other circuits of the
J 44152 jumper
harness.
⇒ | If less than the specified value, the affected circuits are shorted together. |
- Using the light blue J 35616-64B probes, test for greater than 10K ohms between the ISS low signal circuit, jumper harness terminal V, and all other circuits of the
J 44152 jumper
harness.
⇒ | If less than the specified value, the affected circuits are shorted together. |
- Using the light blue J 35616-64B probes, test the ISS high signal circuit for less than 10 ohms between the
J 44152 jumper harness terminal S and terminal 11 PCM X3.
⇒ | If greater than the specified value, repair the open or high resistance in the affected circuit. |
- Using the light blue J 35616-64B probes, test the ISS low signal circuit for less than 10 ohms between the
J 44152 jumper harness terminal V and terminal 49 PCM X3.
⇒ | If greater than the specified value, repair the open or high resistance in the affected circuit. |
- Using a 5A fused jumper wire and the light blue J 35616-64B probes, test for greater than 10K ohms between the ISS high signal circuit, terminal 11 PCM X3, and all other circuits of PCM X3.
⇒ | If less than the specified value, the affected circuits are shorted together. |
- Using a 5A fused jumper wire and the light blue J 35616-64B probes, test for greater than 10K ohms between the ISS low signal circuit, terminal 49 PCM X3, and all other circuits of PCM X3.
⇒ | If less than the specified value, the affected circuits are shorted together. |
- If all circuits and connections test normal, replace the PCM.
Component Testing
- Ignition OFF, using the
J 44257 main wiring harness connector remover, disconnect the automatic transmission inline 20-way connector and install the
J 44152 jumper
harness on the transmission pass-thru connector.
- Using the light blue J 35616-65B test probe from the J 35616-D GM terminal test kit, test for between 820-1,428 ohms between the ISS high signal circuit, jumper harness pin S, and the ISS low signal
circuit, jumper harness pin V.
⇒ | If greater than the specified range, test the affected circuits for an open/high resistance. If both circuits test normal, replace the ISS. |
⇒ | If less than the specified range, test the affected circuits for a shorted together condition. If both circuits test normal, replace the ISS. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.