TF1 - Check TSS/OSS Connector Continuity

Diagnostic Trouble Code (DTC) 639 indicates frequency or voltage of the Turbine Shaft Speed (TSS) / Output Shaft Speed Sensor (OSS) is insufficient to the Powertrain Control Module (PCM).

Possible causes:
- Open circuit in harness.
- Short circuit in harness.
- Damaged TSS/OSS.
- Damaged PCM.

- Key "OFF".

- Disconnect TSS/OSS.

- Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- Measure resistance between test pin 5 at the breakout box and TSS+/OSS+ circuit at TSS/OSS vehicle harness connector.

- Measure resistance between test pin 46 at the breakout box and SIG RTN circuit at the TSS vehicle harness connector.

- Is each resistance less than 5.0 ohms?

Yes -- Go to TF2. TF2 - Check TSS/OSS Harness Circuit For Short to Power/Ground

No -- Service open circuit. Remove breakout box. Reconnect all components. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)