CM850 Electronic Control System – FAULT CODE 284

Engine Speed/Position Sensor (Crankshaft) Supply Voltage Circuit –
Voltage Below Normal or Shorted to Low Source


Overview

CODE REASON EFFECT
Fault Code: 284
PID: S221
SPN: 1043
FMI: 4/4
LAMP: Amber
SRT: 

Engine Speed/Position Sensor (Crankshaft) Supply Voltage Circuit –
Voltage Below Normal or Shorted to Low Source. Low voltage detected on the ECM voltage supply line to engine speed sensor.

Possible hard starting and rough running.

Engine Speed Sensor Circuit
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Circuit Description

The engine speed voltage supply provides +5 VDC for the engine speed sensor. If the supply wire to this sensor is damaged, the sensor will not work properly.

Component Location

The engine speed sensor is located on the intake side of the engine between number 5 and number 6 cylinders at the crankshaft level. Refer to Procedure 100-002 for detailed component view location.

Shop Talk

Low voltage on the +5 VDC supply line can be caused by a short circuit to ground in a supply line, a short circuit between a supply line or a return line, a failed sensor, or a failed ECM power supply.

Refer to Troubleshooting Fault Code t05-284

Last Modified:  08-Jul-2010