PACCAR PX-9 CM2350 (2013-17) Fault Code:115 PID:190 SPN:612 FMI:2 Engine Magnetic Speed/Position Lost Both of Two Signals – Data Erratic, Intermittent, or Incorrect

Reason:
Engine Magnetic Speed/Position Lost Both of Two Signals – Data Erratic, Intermittent, or Incorrect. The ECM has detected the primary and backup speed sensor signals are connected backwards.

Effect:
The engine will shut down or will not start.

Circuit Description:
The crankshaft position and camshaft position sensors are Hall effect type sensors. The engine control module (ECM) provides a 5 volt supply to the position sensor and a return circuit. As the teeth on the crankshaft speed ring or the dimples in the back of the camshaft gear move past the position sensor, a signal is generated on the position sensor signal circuit. The ECM interprets this signal and converts it to an engine speed. A missing tooth on the crankshaft gear is used by the ECM to determine the position of the engine.

Component Location:
The crankshaft position and camshaft position sensor location varies, depending on engine model.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the crankshaft position and camshaft position signal inputs to the ECM are reversed.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the red STOP ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
3) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
This fault code indicates the crankshaft position sensor and the camshaft position sensor wiring harness connectors are reversed. As a result, the engine will not start.

Possible Causes:
1) Bad ECM