Test DJ: Step 5

5) Checking RPM Sensor Resistance  With key off and RPM sensor disconnected, set DVOM on 200,000 ohm scale. Measure resistance across the terminals of the RPM sensor. If resistance is between 2400-2800 ohms, replace ECA, remove breakout box and repeat QUICK TEST. If resistance is not between 2400-2800 ohms, diagnose the tachometer. Refer to DIESEL TACHOMETER article in the ACCESSORIES & EQUIPMENT section.