ECT3 - SIG RTN Circuit

- Key OFF.

- Install Breakout Box (leave PCM disconnected).

- Disconnect the ECT sensor connector.

- Measure the resistance between BOB Test Pin SIGRTN and SIGRTN terminal at the ECT sensor harness connector.

- Is the resistance less than 5 ohms?

Yes -- Replace the ECT sensor.

No -- Service the SIGRTN wire between PCM and ECT sensor connector.