System Diagnostics; On-Board Fault Detection System; Triumph Diagnostic Tool - Triumph Rocket III Classic Service Manual

Fuel System/Engine Management
System Diagnostics
The engine management system has an on-board
diagnostics feature which allows service technicians to
retrieve stored data from the ECM using a Triumph
service tool. Full details of the tool's operation and how to
interpret the results are given elsewhere in this section.
The tool is connected to the motorcycle using a dedicated
diagnostic plug situated beneath the seats. By using a
dedicated plug, no electrical connectors associated with
the system are disturbed, reducing potential connector
damage.
The tool allows the user to retrieve data associated with
the system sensors and actuators, test various component
functions, read build data and make minor adjustments to
the set-up of the system. The data and tests available are
described on the following pages.
On-board Fault Detection System
The on-board diagnostic system has two stages to fault
detection. When a fault is detected, the DSM (Diagnostic
Status Manager) raises a flag to indicate that a fault is
present and increments a counter. The counter checks the
number of instances that the fault is noted. For example, if
there is a fault in the crankshaft position sensor, the
counter will increment its count each time the crankshaft
turns through 360·, provided the fault is still present.
When the count begins, the fault is detected but not
confirmed. If the fault continues to be detected and the
count reaches a pre-determined threshold, the fault
becomes confirmed. If the fault is an emissions related
fault or a serious malfunction affecting engine
performance, a DTC (Diagnostic Trouble Code) and
freeze-frame data will be logged in the ECM's memory
and the MIL (Malfunction Indicator Lamp) on the
motorcycle instrument panel is illuminated. Once a fault is
confirmed, the number of warm-up cycles made by the
engine is counted. If the fault clears, the warm-up cycle
counter will extinguish the MIL (Malfunction Indicator
Lamp) at a pre determined count, and erase the DTC and
freeze frame data from the ECM memory at another
(higher) count.
A single warm-up cycle is deemed to have taken place
when the following criteria have been met:
The coolant temperature must be raised to
n·c
or more.
The coolant temperature must have risen by
23·C or more from its start temperature, when
n·c
is reached.
A controlled power-down sequence must take
place.
Note:
• When a fault has been rectified, the MIL will
remain illuminated until sufficient non-fault
warm-up cycles have taken place to turn it off.
The MIL will be immediately extinguished if,
after first rectifying the fault, the DTC
(diagnostic trouble code) that caused the MIL
illumination is erased from the ECM memory
using the Triumph diagnostic tool.
Note:
• In most cases, when a fault is detected, the
engine management system will revert to a
'limp-home' mode. In this mode, the engine
will still function though the performance and
fuel economy may be marginally affected. In
some cases, the rider may not notice any
appreciable difference from normal operation.
Triumph Diagnostic Tool
Described on the following pages is the range of
information which can be retrieved from the ECM's
memory and the adjustments which can be performed
using the Triumph service diagnostic tool.
The tables indicate which tests are performed by the on-
board system and what information can be retrieved by
the Triumph diagnostic tool.
Full details of how to operate the tool and how to interpret
the data follow later in this section.
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Service Manual - Rocket III / Classic / Touring