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TROUBLE CODE 21
ACTIVE MUFFLER CONTROL (XB12
MODELS ONLY)
The interactive exhaust system utilizes an actuator valve in
the muffler which is connected to a servo motor via a cable.
The valve position automatically adjusts to enhance engine
performance.
A Code 21 will set if the ECM detects that the output for the
Interactive Muffler Control Actuator is not in agreement with
the feedback circuit.
●
Mechanical fault in the actuator, valve or cable.
●
Electrical fault in the actuator circuit.
●
Electrical fault in the actuator feedback circuit.
See B.5 INDEX TO WIRING DIAGRAMS.
4.21
bs0026xx
Empty
39
33
Diode
40
Battery
41
The reference numbers below correlate with the circled numbers on the Code 21 flow charts.
1.
Using TEST CONNECTOR KIT (Part No. HD-41404),
attach red probe and patch cord to [164B].
2.
Using TEST CONNECTOR KIT (Part No. HD-41404),
use gray male pin probe and patch cord.
4-64
2005 Buell Lightning: Fuel System
35
42
36
Lights
37
Key Sw
44
38
21
Acces.
22
28
Bk/Hn/Mflr
23
29
Fan
ECM
43
DIAGNOSTIC NOTES
34
IGN
27
30
24
Spare
31
25
Spare
32
26
Figure 4-42. Fuses and Diodes
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b1073a4x
INTERACTIVE MUFFLER SUB HARNESS
MUFFLER VALVE
ACTUATOR
MOTOR
DC
POSITION
SENSOR
CONTROL ELECTRONICS
1
2
3
4
1 O
2 BK
3 W
4 TN/V
[161A]
[161B]
BRAKE/HORN/MUFFLER
9
3
R/BK
[164A]
[164B]
O
W
TN/V
165A]
O
O 1 1
W 2 2
TN/V 3 3
165B]
GROUND
Figure 4-43. Interactive Exhaust Circuit
2005 Buell Lightning: Fuel System
4-65
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Code 21 Test
Remove airbox cover and foam from on top
of interactive muffler control actuator.
YES.
Actuator opens and closes
2-6 seconds later
With the throttle in the wide open position,
Ignition on, Run/Stop on. Does the actuator
cycle smoothly?
YES.
Opens and closes
immediately.
NO
1
1
Disconnect [164] from ECM. Key on,
ground opposite end of patch cord.
Does the actuator cycle?
Connect BREAK OUT BOX and measure voltage
between pin 2 (Black) (-) and pin 9 (Black) (+). Disconnect terminal [164] from ECM. With Ignition on, Ground
opposite end of patch cord. When grounded, voltage
should be between 4-6 VDC, and 0-1 VDC when not
grounded.
NO
Replace ECM
Check continuity to ground at
pin 2, [161B].
Continuity present?
2
YES
System OK.
Clear codes.
NO
YES
2
Check continuity between pin 9 (Black) and
[161B] pin 4. Continuity present?
Locate and repair
open on TN/V wire
[161B].
NO
YES
2
Locate and repair open on
BK wire.
NO
Ignition on, Run/Stop in Run
position. 12V present at pin 1,
[161B]?
YES
1
Check for continuity to ground on pin 9
(Black) with ECM disconnected.
Continuity present?
YES
Locate and repair open on
O wire between fuse and
[161B].
NO
Check for continuity between
[164B] and [161B] pin 3.
Continuity present?
YES
Locate and repair open on
W wire.
NO
YES
Locate and repair
short to ground on
TN/V wire [161B].
NO
2
With ECM connected, measure
voltage at [161B] pin 4.
0V
Replace ECM
4-66
Using pliers, gently pull on cable to
interactive muffler actuator. Cable
should cause interactive muffler valve
to open and close freely without bind-
4-6 v
Replace interactive motor.
12V
Locate and repair
short to voltage on
TN/Y wire.
2005 Buell Lightning: Fuel System
YES
Replace interactive muffler
actuator.
NO
Disconnect cable to interactive valve. Does valve
arm move freely without
binding?
YES
Replace interactive muffler
cable.
NO
Replace muffler
assembly