Catalyst Over Temperature – Data Valid but Above Normal Operational Range – Most Severe Level
|Fault Code: 1687
Catalyst Over Temperature – Data Valid but Above Normal Operational Range – Most Severe Level. Very high temperatures have been detected in the aftertreatment system.
Catalyst solution injection into the aftertreatment system is disabled.
Circuit: Aftertreatment Control System
The Exhaust Gas Temperature Number 2 sensor is used by the ECM to monitor the engine exhaust gas temperature exiting the catalyst unit. The ECM monitors the voltage on the signal pin and converts this to a temperature value.
The catalyst exhaust gas temperature sensor is located in the aftertreatment system. It is located at the outlet of the catalyst exhaust system.
This fault is triggered when the temperature at the catalyst exhaust outlet exceeds the maximum allowable temperature for a given engine rating.
On-Board Diagnostic (OBD) Information:
- The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The ECM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. The MIL lamp and fault code can also be cleared with INSITE™ electronic service tool.
- The fault code will be cleared from the memory after 40 consecutive drive cycles when the diagnostic runs and passes.