Check Input Signal For ECM

Turn the ignition switch to ON. (Engine OFF)

Measure the voltage between ECM connector and chassis ground.

Connector & terminal 

(B136) No. 20 (+) - Chassis ground (- ): 

Is the voltage less than 0.12 V?

YES. Go to  CHECK INPUT VOLTAGE OF ECM  . 

NO. Go to  CHECK HARNESS BETWEEN ECM & COMBINATION METER  .