Diagnostic Instructions
DTC Descriptor
DTC P150A: Transmission Output Speed Signal Circuit
DTC P150B: Transmission Output Speed Sensor Circuit Intermittent
Circuit/System Description
The vehicle speed sensor (VSS), also called the output shaft speed sensor (OSS) creates an AC voltage as the rotor teeth pass through the magnetic field of the sensor. The transmission control module (TCM) converts the AC voltage into
a vehicle speed signal, which is used to determine shift timing and torque converter clutch (TCC) scheduling. The TCM also provides a replicated transmission output speed signal (RTOSS) to the engine control module (ECM).
Conditions for Running the DTC
P150A
| • | The TCM indicates the transmission output speed signal is valid. |
| • | Transmission output speed is 1,200 RPM or greater. |
P150B
| • | Transmission output speed is greater than 300 RPM for 2 seconds. |
| • | Transmission output speed has changed less then 500 RPM for 2 seconds. |
Conditions for Setting the DTC
P150A
The replicated output speed is 60 RPM or less for 4.5 seconds.
P150B
The change in replicated output speed is 350 RPM or greater for 3.25 seconds.
Conditions for Clearing the DTC
P150A
| • | The replicated output speed is 150 RPM or greater for at least 3 seconds. |
P150B
| • | Transmission output speed is 150 RPM or greater for at least 2 seconds. |
| • | The change in transmission output speed is 150 RPM or less for at least 3 seconds. |
Diagnostic Aids
| • | A defective transmission output speed sensor (OSS) can cause inaccurate speed reading, creating faulty replicated output speed signal. Also, inspect the OSS for cracks, loose mounting, or damage. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Transmission General Information
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Transmission Control Module Scan Tool Information
Circuit/System Verification
If there are any other engine or transmission related DTCs set, diagnose those DTCs first. With a scan tool, observe the transmission output shaft speed sensor parameter for appropriate output RPM. Then in the engine controls data list, look for a functioning
signal from the TCM.
Circuit/System Testing
- Ignition OFF, disconnect the ECM connector (X3).
- Ignition ON, measure the voltage on the harness of the ECM connector (X3-66) for 5 V.
| ⇒ | If you have 5 V, test or replace the ECM. |
| ⇒ | If the value is other than 5 V, test harness for: |
- If no trouble found, replace the TCM.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the repair.
Control Module References
for ECM replacement, setup, and programming.
