DTC P0720 or P0722
Diagnostic Instructions
DTC Descriptors
| DTC P0720: Output Speed Sensor Circuit
Performance |
| DTC P0722: Output Speed Sensor Circuit No
Signal |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
OSS Supply Voltage
|
P0720
|
P0720
|
-
|
P0720
|
OSS Signal
|
P0720, P0722
|
P0720, P0722
|
P0720, P0722
|
-
|
|
| |
Typical Scan Tool Data
Transmission OSS
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Operating Conditions: Engine running,
normal operating temperature
Parameter Normal Range: 0-7 000 RPM
|
OSS Supply Voltage
|
Out of Range
|
Out of Range
|
OK
|
OSS Signal
|
0 RPM
|
0 RPM
|
0 RPM
|
|
| |
Circuit/System Description
The output shaft speed sensor (OSS) is a hall-effect type
sensor. The sensor faces the output shaft machined teeth surface.
As the output shaft rotates, the sensor produces a signal frequency
based on the machined surface of the output shaft. This signal is
transmitted to the Transmission Control Module (TCM). The TCM uses
the OSS signal in connection with the input speed sensor signal to
control engine torque, shift timing, and lock-up.
Conditions for Running the DTC
P0720
| • |
The ignition voltage is
10.2-15.5 V. |
| • |
The engine speed is greater
than 400 RPM for 2 s. |
| • |
The transmission is not in
emergency mode. |
| • |
TCM communication is
normal. |
| • |
Vehicle speed by ABS is
greater than 30 km/h (19 MPH). |
P0722
| • |
The ignition voltage is
10.2-15.5 V. |
| • |
The engine speed is greater
than 400 RPM for 2 s. |
| • |
The transmission is not in
emergency mode. |
| • |
TCM communication is
normal. |
Conditions for Setting the DTC
P0720
Deviation from calculated output speed is more than 15% for 1 s
over 10 times.
P0722
| • |
Deviation from calculated
output speed is more than 300 RPM. |
| • |
No output speed sensor pulse
while receiving pulses on the input speed sensor. |
| • |
No output speed sensor pulse
when vehicle speed from ABS is more than 20 km/h (13 MPH) for 300
ms. |
Action Taken When the DTC Sets
| • |
DTCs P0720 and P0722 are Type
A DTCs. |
| • |
The TCM freezes transmission
adaptive functions. |
| • |
The TCM turns OFF all
solenoids. |
| • |
The TCM allows the vehicle
after a stop to operate only in the second gear and "R"
range. |
Conditions for Clearing the DTC
| • |
DTCs P0720 and P0722 are Type
A DTCs. |
| • |
Output speed is greater than
300 RPM for more than 70 s. |
| • |
Deviation from calculated
output speed is less than 5% for more than 1 s. |
Diagnostic Aids
| • |
Damage or misalignment of the
counter drive gear machined teeth surface may cause a speed sensor
malfunction. |
| • |
Proper torque of the OSS
mounting bolt is critical to proper OSS operation. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
Description and Operation
Transmission Component and System Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
| 1. |
Operate the vehicle at 16-32
km/h (10-20 MPH) while observing the scan tool Transmission OSS
parameter. The Transmission OSS should vary with the vehicle speed
and not drop out. |
| 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
observe from the Freeze Frame/Failure Records data. |
Circuit/System Testing
Static Test
| 1. |
Ignition OFF, remove the K71
Transmission Control Module. |
| 2. |
Test for more than 1 MΩ
between the low reference circuit terminal 20 X2 and the voltage
supply circuit terminal 19 X2. |
| ⇒ |
If less than the specified range, test the wiring
harness for internal short. If the circuit test normal, replace the
automatic transmission. |
| 3. |
Test for infinite resistance
between each terminal and the low reference circuit terminal 20 X2
and also to the voltage supply circuit terminal 19 X2. |
| ⇒ |
If less than the specified range, replace the
wiring harness. |
| 4. |
If all circuits test normal,
test or replace the K71 Transmission Control Module. Verify the DTC
does not reset. |
| ⇒ |
If the DTC resets, replace the automatic
transmission. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|
