Allison - Automatic Transmission
DTC P0716 or P0717
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0716
- Turbine Input Speed Sensor Performance
DTC P0717
- Turbine Input Speed Low
Circuit/System Description
The transmission turbine speed sensor is a permanent magnet surrounded by a coil of wire that is mounted to the transmission case. This sensor is positioned next to the PTO drive gear or tone wheel that is attached to the 1-2-3-4-5-6 Clutch Piston Housing. The housing rotates with the torque converter turbine so that the gear teeth on the PTO or bars on the tone wheel cross the magnetic field and generates an AC current. The voltage output and frequency generated by the sensor will vary as the gear or tone wheel changes speed. The speed sensor signal wires are twisted to cancel magnetically induced fields. The transmission control module (TCM) changes the speed sensor analog signal into a digital signal. The TCM uses turbine speed for shift control, line pressure and speed ratio calculations.
Conditions for Running the DTC
P0716 Condition 1
* DTC P0716, P0717, P0721, or P0722 is not set.
* A shift is not in progress.
* The engine speed is 200 RPM or greater.
P0716 Condition 2
* DTC P0716, P0717, P0721, or P0722 is not set.
* A shift is not in progress.
P0716 Condition 3
* DTC P0716, P0717, P0721, or P0722 is not set.
* A shift is not in progress.
* The turbine speed is greater than 100 RPM.
* The engine speed is greater than 100 RPM.
P0717 Condition 1
* DTC P0721, P0722, P0729, P0731, P0732, P0733, P0734, P0735, and P0736 is not set.
* A shift is not in progress.
* The engine speed is 200 RPM or greater.
* The range attained is not neutral.
* The transmission fluid temperature is greater than -25°C (-13°F).
P0717 Condition 2
* DTC P0721, P0722, P0729, P0731, P0732, P0733, P0734, P0735, and P0736 is not set.
* A shift is not in progress.
* The range attained is not neutral.
* The transmission fluid temperature is greater than -25°C (-13°F).
* The engine speed is 400 RPM or greater.
* The transmission output speed is greater than 150 RPM.
Conditions for Setting the DTC
P0716 Condition 1
The TCM detects an unrealistic change in turbine speed.
P0716 Condition 2
The TCM detects a noisy turbine speed signal.
P0716 Condition 3
The TCM detects a ratio of turbine speed to engine speed of 3 or greater.
P0717 Condition 1
The TCM detects an unrealistic change in turbine speed.
P0717 Condition 2
The turbine speed is less than 61 RPM and the output speed is greater than 500 RPM for 1 second.
Action Taken When the DTC Sets
P0716 or P0717
* DTCs P0716 and P0717 are Type A DTCs.
* If the DTC sets in a forward range, the transmission locks in current range.
* While diagnostic response is active, if the shift selector is moved to NEUTRAL, the transmission will shift to NEUTRAL. If the shift selector is moved to REVERSE, the transmission will shift to REVERSE. If the shift selector is moved to a forward range, the transmission will shift to fourth range.
* The TCM inhibits torque converter clutch (TCC) engagement.
Conditions for Clearing the DTC
DTCs P0716 and P0717 are Type A DTCs.
Diagnostic Aids
You will have to drive the vehicle in order to experience a condition.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Allison - Automatic Transmission)
Connector End View Reference
* Component Connector End Views (Connector End Views By Name)
* Inline Harness Connector End Views (Connector End Views By Number)
Description and Operation
* Transmission General Description (Transmission General Description)
* Transmission Component and System Description (Transmission Component and System Description)
* Electronic Component Description (Electronic Component Description)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Control Module References) for scan tool information
Special Tools
J 38522 - Variable Signal Generator
Circuit/System Verification
1. Engine running, transmission in PARK, use the scan tool to observe the turbine speed while varying the engine speed. The transmission turbine speed parameter should vary with the engine speed.
2. 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
Note: You must perform the Circuit/System Verification first.
1. Ignition OFF, remove the turbine speed sensor connector.
2. Connect the J 38522 - signal generator to the turbine speed sensor circuit, terminals A and B.
3. Adjust the J 38522 - signal generator to 30 V, frequency to 1K Hz and duty cycle to 50 percent.
4. Ignition ON, engine OFF, use a scan tool to verify the Turbine Speed parameter is between 900 to 1000 RPM.
• If not the expected value, check the turbine speed signal and ground circuits for an open/high resistance, short to ground, or a short to voltage. If circuits test normal, replace the TCM. Refer to Control Module References (Control Module References) for TCM replacement, setup, and programming.
5. Test or replace the turbine speed sensor. Refer to Speed Sensor Replacement (Allison - Automatic Transmission).
Component Testing
Static Testing
Note: You must perform the Circuit/System Testing first.
1. Ignition OFF, remove the turbine speed sensor. Refer to Speed Sensor Replacement (Allison - Automatic Transmission).
2. Test for resistance between terminal A and terminal B of the turbine speed sensor. See the Speed Sensor table, refer to Temperature Versus Resistance (Transmission Fluid Temperature Sensor) (Temperature Versus Resistance (Transmission Fluid Temperature Sensor))Temperature Versus Resistance (Speed Sensor) (Temperature Versus Resistance (Speed Sensor))Temperature Versus Resistance (Solenoid) (Temperature Versus Resistance (Solenoid)).
• If not within the specified range, replace the speed sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Wiring Harness Replacement (Allison - Automatic Transmission)
* Speed Sensor Replacement (Allison - Automatic Transmission)
* Control Module References (Control Module References) for TCM replacement, setup, and programming
Repair Verification
If another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) and perform the appropriate diagnostic procedure.