CM850 Electronic Control System – FAULT CODE 115

Engine Magnetic Crankshaft Speed/Position Lost Both of Two Signals
– Data Erratic, Intemittent, or Incorrect


Overview

CODE REASON EFFECT
Fault Code: 115
PID: P190
SPN: 612
FMI: 2
LAMP: Red
SRT: 

Engine Magnetic Crankshaft Speed/Position lost both of two signals –
Data Erratic, Intermittent, or Incorrect. The ECM has detected that the primary engine speed sensor and the backup engine speed sensor signals are reversed.

Fueling to the injectors is disabled, and the engine can not
be started.

Engine Speed Sensor and Camshaft Position Sensor Circuit
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Circuit Description

The main engine speed sensor (crankshaft position sensor) and the backup engine speed sensor (camshaft position sensor) are connected to the engine wiring harness.

Component Location

The main engine speed sensor (crankshaft position sensor) reads a tone wheel that is mounted to the front of the engine crankshaft. The backup engine speed sensor (camshaft position sensor) reads a tone wheel that is inside the front cover.

Shop Talk

The main engine speed sensor (crankshaft position sensor) and the backup engine speed sensor (camshaft position sensor) are located in close proximity to one another. The same sensor is used in both locations. (Connector key is the same.) A P-clip on the engine wiring harness prohibits the harness connectors from being connected to the incorrect sensors. However, if the P-clip is omitted, it is possible to plug the wiring harness connectors into the incorrect sensors. If this occurs, the ECM will detect the problem and the engine will not start. Once the connector problem is corrected, the engine can be started and the fault code will become inactive.

Refer to Troubleshooting Fault Code t05-115

Last Modified:  08-Jul-2010