Check Engine RPM Sensor
engine
Description
The engine RPM is sensed below 1000 on a second or third start attempt, and the unit gives an alarm only and considers the engine running.
Activation Conditions
If ambient temperature is above 32°F (0°C), and this is the second or third start attempt, and the engine oil pressure switch is closed (oil pressure good), and engine speed is sensed at less than 1000; OR, if ambient is below 32°F (0°C) and the DC amp draw is more than 2 amps, and this is the second or third start attempt, and engine speed is sensed at less than 1000.
Unit Behavior
Engine Operation: Alarm Only and engine will be considered running. Electric Operation: This alarm does not activate in electric operation.
Reset Conditions
Auto reset when engine speed is greater than 1,000 rpm or alarm may be manually reset using the display mounted keys or by turning the unit off, then back on again.
Corrective Actions
1. Check for Alarm 00041 Engine Stalled - When alarms 00041 and 00130 occur at the same time, generally, the engine has run out or is running out of fuel. This causes the engine to surge. Check fuel in tank and add fuel as necessary. Check fuel lines between the fuel tank and the fuel pump inlet to ensure air is not being drawn in. 2. Check Engine Speed Sensor (ENSSN) a. Check actual engine speed using a hand held tachometer and compare with speed shown in unit data. Must be ± 20 rpm. Must be a steady reading. b. Inspect sensor, connector pins and terminals. Verify there is no physical damage to sensor, and no damage or corrosion in connections. c. Check power from ECU. Should read approximately +12 VDC from terminal ENCU-39 to ENSSN-1. d. Check ground to ECU. Check wiring from terminal ENCU-08 to ENSSN-3. e. Check signal to ECU. Check wiring from terminal ENCU-75 to ENSSN-2. 3. Check Circuits With Test Sensor - Substitute known good sensor and check unit data reading (Refer to Section 3.15). Must be within ± 50 rpm of reading on tachometer.