CM870 and ISX Engines – FAULT CODE 689

Engine Speed Sensor Circuit


Fault Code: 689
PID: P190
SPN: 190
FMI: 2/2
LAMP: Amber

Primary Engine Speed Sensor Error. The ECM has detected an error in the engine speed signal.

Engine power derate.

Engine Speed Sensor Circuit

Circuit Description

The engine speed sensor monitors engine speed and position then passes this information to the electronic control module (ECM) through the engine harness.

Component Location

The engine speed sensor is located on the side of the front gear housing on the intake side of the engine. Refer to Procedure 100-002 in Section E.

Shop Talk

This fault is logged when the ECM does not receive a valid engine speed signal. Causes of this fault include:

  • Open or short circuit of the +5 volt supply, signal, or return wire in the engine harness
  • Damaged or malfinctioning engine speed sensor.

Refer to Troubleshooting Fault Code t05-689

Last Modified:  02-Sep-2010