Briggs & Stratton Vanguard EFI 380000, Руководство по ремонту

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DIAGNOSTIC INTRODUCTION
On-Board Diagnostic (OBD) System Check
The basic steps of any diagnosis are as follows:
1. See Figure 1. Observe the Malfunction Indicator
Lamp (MIL) with the engine running. If MIL is flashing,
then current Diagnostic Trouble Codes (DTCs) are
present.
NOTE: If engine will not start, install Briggs & Stratton
Service Power Supply Harness (Part No. 847252)
to observe MIL. See Install Service Power Supply
Harness for more information.
2. Read DTC(s) using MIL, Tiny Scan Code Reader,
or Diagnostic Tool software.
3. To diagnose system problem(s), proceed to the
applicable Diagnostic Table(s) in SECTION 2 -
TROUBLESHOOTING DTCs .
4. Once the problem is located and corrected through
repair or replacement of faulty components, clear
DTC(s) using the Tiny Scan Code Reader or
the Diagnostic Tool software.
NOTE: For information on the location or replacement
of specific components, see SECTION 5 -
REMOVAL/INSTALLATION .
5. Start and run engine to validate repairs. Observe MIL
to verify that no DTCs are set.
6. If no DTCs are set, but engine performance issues
exist, see SECTION 4 - SYMPTOMS .
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Diagnostic Trouble Codes (DTCs)
The ECM receives voltage signals from multiple sensors.
Each sensor functions within an established set of
parameters, which can be viewed as its operating
“window.”
When a malfunction or fault condition occurs, a change
in the signal voltage alerts the ECM that the sensor is
functioning outside its operating “window,” a DTC is set
and stored in ECM memory, and the MIL is illuminated.
A default value temporarily replaces the erroneous sensor
value to restore engine performance until the problem is
corrected.
Malfunction Indicator Lamp (MIL)
As a bulb and diagnostic system check, the MIL
illuminates when the engine is cranked. If it does not
illuminate during cranking, then a problem exists in the
MIL circuit.
When the engine is started, the MIL is extinguished if no
current fault condition exists. If the MIL flashes, it is an
indication that a current DTC is stored.
If the fault should correct itself, as in an intermittent
condition, the MIL is extinguished after a ten second
delay. The DTC remains stored in ECM memory as a
historic code until cleared by the technician. The MIL
does not indicate the existence of only historic codes.
Data Link Connector (DLC)
The DLC provides for direct communication with the
ECM. By plugging the Tiny Scan Code Reader, or laptop
with Diagnostic Tool, into the 6-pin connector in the EFI
wire harness, the DTCs stored in ECM memory can be
read and cleared.
Non-Scan Diagnostics
In the Non-Scan diagnostic mode, either the MIL or
the Tiny Scan Code Reader is used to read DTCs. The
technician then refers to the applicable Diagnostic Table
to troubleshoot the problem. Those tables labeled Non-
Scan Diagnostics must be used, as the data stream
provided by the ECM is not available for analysis.
Scan Diagnostics
In the more sophisticated diagnostic mode, the Diagnostic
Tool software can facilitate the diagnosis of system
problems through an expanded interface with the ECM.
Through the use of data displays and menu selections,
the technician has access to “live” data for analysis.
It is important to note that the software is not a stand-
alone diagnostic tool for resolving DTCs, but must be
used in conjunction with the Diagnostic Tables for the
most efficient and effective diagnosis. Those tables that
are applicable to users with access to the Diagnostic
Tool software are labeled as Scan Diagnostics .
Not for
Reproduction