Malfunction in tachometer

1. 1
   Check output value of ecm.
2. 2
   Connect the hand–held tester to dlc3.
3. 3
   Turn the ignition switch to on and push the hand–held tester main switch on.
4. 4
   Select the data list mode on the hand–held tester.

   

   

(Reference) inspection using oscilloscope

1. 1
   check the input signal waveform.
2. 2
   Remove the combination meter assy with connectors still connected.
3. 3
   Connect the oscilloscope to the terminals c9–19 of combination meter assy and body ground.
4. 4
   Start engine.
5. 5
   Check the signal waveform.

   

   

   

   

1. 1
   Remove the combination meter.
2. 2
   check the continuity between terminals 5 (tach) of ecm and c9–19 of combination meter connector.

Standard: there is continuity.