2009 INFINITI QX56 relay

TRANSFER CONTROL UNITDLN-85
< ECU DIAGNOSIS > [ATX14B]
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PHYSICAL VALUES
Terminal Layout
SHIFT AC MON2 [ON/
OFF] Check signal for transfer
control unit signal output  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 4LO to
4H (Wait function is oper-
ating.)
ON
Except the above OFF
T/F F SPEED [km/h] or
[mph] Displayed, but do not use.
A/T R SPEED [km/h] or
[mph] Condition of vehicle
speed sensor A/T (output
speed sensor)
During driving Approximately
matches the out-
put shaft speed.
AT GEAR POSI [1/2/3/4/
5] Condition of A/T selector
lever position
Displays actual A/T gear position. 1
2
3
4
5
Monitored item [Unit] Content Condition Display value
WDIA0378E
Te r m i n a l
Wire
color Item Condition Data (Approx.)
1 GR 2-4WD shift solenoid valve  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: 2WD 0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage
2 B/W 4WD shift indicator lamp
(2WD indicator lamp) 2WD indicator lamp: OFF Battery voltage
2WD indicator lamp: ON 0V
3 B Ground Always 0V
4 Y/L Transfer shift high relay  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de-
pressed 4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
5 W/B 4WD warning lamp 4WD warning lamp: ON 0V
4WD warning lamp: OFF Battery voltage
6 B Ground Always 0V
7 L CAN-H — —
8 P CAN-L — —
9G/W 4WD shift switch
(2WD) Ignition switch: ON4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V
Revision: December 20092009 QX56

DLN-86
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
10 L/W Transfer dropping resistor Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: AUTO 4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
11 L 4WD shift indicator lamp
(Lock indicator lamp) Lock indicator lamp of 4WD shift indicator lamp: OFF Battery voltage
Lock indicator lamp of 4WD shift indicator lamp: ON 0V
12 W/G 4LO indicator lamp 4LO indicator lamp: OFF Battery voltage
4LO indicator lamp: ON 0V
13 G/B Transfer shift low relay  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de-
pressed 4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
14 LG Transfer motor relay  Accelerator pedal
depressed
 Vehicle stopped
 Engine running
 Brake pedal de- pressed 4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position)
Battery voltage
(0V for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position) 0V
4WD shift switch: 4H (A/T selector lever
“P” position) Battery voltage
(0V for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position) 0V
15 L/B ATP warning lamp ATP indicator lamp: ON 0V
ATP indicator lamp: OFF Battery voltage
16 Y/R Power supply Ignition switch: ON Battery voltage
Ignition switch: OFF 0V
18 O 4WD shift switch
(4H) Ignition switch: ON4WD shift switch: 4H Battery voltage
4WD shift switch: 2WD, AUTO or 4LO 0V
19 L Clutch pressure solenoid
valve  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: AUTO 1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
21 BR 4WD shift indicator lamp
(AUTO indicator lamp)  AUTO indicator lamp of 4WD shift indicator lamp: OFF Battery voltage
AUTO indicator lamp of 4WD shift indicator lamp: ON 0V
22 Y/R Power supply Ignition switch: ON Battery voltage
Ignition switch: OFF 0V
23 R 4WD shift switch
(4LO)
Ignition switch: ON4WD shift switch: 4LO Battery voltage
4WD shift switch: 2WD, AUTO or 4H 0V
24 LG/R 4WD shift switch
(AUTO)
Ignition switch: ON4WD shift switch: AUTO Battery voltage
4WD shift switch: 2WD, 4H or 4LO 0V
Te r m i n a l
Wire
color Item Condition Data (Approx.)
Revision: December 20092009 QX56

TRANSFER CONTROL UNITDLN-87
< ECU DIAGNOSIS > [ATX14B]
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25 V Neutral-4LO switch  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)
Battery voltage
→
0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.) 0V
→ Battery
voltage
4WD shift switch: 4LO 0V
27 W/L Actuator position switch 2
(High)  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de-
pressed 4WD shift switch: 4H, AUTO or 2WD 0V
4WD shift switch: 4LO Battery voltage
28 B/G Sensor ground Always 0V
29 L/W Ignition switch monitor Ignition switch: ON Battery voltage
Ignition switch: OFF 0V
30 SB Shut off relay Ignition switch: ON 0V
Ignition switch: OFF Battery voltage
31 G Transfer fluid temperature
sensor
Ignition switch: ONTransfer fluid temperature approx. 20
°C
(68 °F) 1.1V
Transfer fluid temperature approx. 80 °C
(176 °F) 0.3V
33 R/L Transfer shift high relay
monitor  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
34 BR Clutch pressure switch  Vehicle stopped
 Engine running
 A/T selector lever
“D” position 4WD shift switch: AUTO or 4H (“Wait” func-
tion is not operating.)
0V
 Vehicle stopped
 Engine running 4WD shift switch: 2WD (“Wait” function is
not operating.)
Battery voltage
35 BR/
W Line pressure switch  Ignition switch: ON
 A/T selector lever “D” position
 4WD shift switch: AUTO
0V
 After the vehicle has been left at
room temperature
for 5 minutes and
more with ignition
switch in “OFF” po-
sition.  Ignition switch: ON
 A/T selector lever: “P” or "N" position
 4WD shift switch: other than AUTO
Battery voltage
40 L/Y ATP switch  Vehicle stopped
 Engine running
 A/T selector lever
“N”
 Brake pedal de- pressed 4WD shift switch: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)
0V
Except the above Battery voltage
Te r m i n a l
Wire
color Item Condition Data (Approx.)
Revision: December 20092009 QX56

DLN-88
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
NOTE:
Data are reference value and are measured between each terminal and ground.
41 RTransfer motor relay moni-
tor  Accelerator pedal
depressed
 Vehicle stopped
 Engine running
 Brake pedal de- pressed 4WD shift switch: 2WD 0V
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position)
0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position) Battery voltage
4WD shift switch: 4H (A/T selector lever
“P” position) 0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position) Battery voltage
42 P/G Transfer shift low relay
monitor  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de-
pressed 4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
43 G/Y Wait detection switch  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)
Battery voltage
→
0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.) 0V
→ Battery
voltage
4WD shift switch: 4LO 0V
44 LG/B Actuator position switch 1
(Low)  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: 4LO 0V
4WD shift switch: 2WD, AUTO or 4H Battery voltage
45 B Ground Always 0V
47 W Power supply
(Memory back-up) Ignition switch: ON Battery voltage
Ignition switch: OFF Battery voltage
Te r m i n a l
Wire
color Item Condition Data (Approx.)
Revision: December 20092009 QX56

DLN-98
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1802] CONTROL UNIT 1 Malfunction is detected in the memory (RAM) sys-
tem of transfer control unit.
Refer to DLN-24
.
[P1803] CONTROL UNIT 2 Malfunction is detected in the memory (ROM) sys-
tem of transfer control unit.
[P1804] CONTROL UNIT 3 Malfunction is detected
in the memory (EEPROM)
system of transfer control unit.
[P1807] VHCL SPEED SEN·AT  Malfunction is detected in output shaft revolution
signal that is output from TCM through CAN com-
munication.
 Improper signal is input while driving. Refer to
DLN-26
.
[P1808] VHCL SPEED SEN·ABS  Malfunction is detected in vehicle speed signal
that is output from ABS actuator and electric unit
(control unit) through CAN communication.
 Improper signal is input while driving. Refer to
DLN-27
.
[P1809] CONTROL UNIT 4 AD converter system of transfer control unit is mal-
functioning. Refer to
DLN-24
.
[P1810] 4L POSI SW TF Improper signal from neutral-4LO switch is input due
to open or short circuit. Refer to
DLN-28
.
[ P 1 8 11 ] B AT T E R Y V O LTA G E Power supply voltage for transfer control unit is ab-
normally low while driving.
Refer to
DLN-22
.
[P1813] 4WD MODE SW More than two switch inputs are simultaneously de-
tected due to short circuit of 4WD shift switch. Refer to
DLN-31
.
[P1814] 4WD DETECT SWITCH Improper signal from wait detection switch is input
due to open or short circuit. Refer to
DLN-35
.
[P1816] PNP SW/CIRC When transmission range switch signal is malfunc-
tion or communication error between the control
units. Refer to
DLN-38
.
[P1817] SHIFT ACTUATOR  Motor does not operate properly due to open or
short circuit in actuator motor.
 Malfunction is detected in the actuator motor. (When 4WD shift switch is operated and actuator
motor is not operated)
 Malfunction is detected in transfer shift high relay and transfer shift low relay. Refer to
DLN-39
.
[P1818] SHIFT ACT POSI SW  Improper signal from actuator position switch is in-
put due to open or short circuit.
 Malfunction is detected in the actuator position
switch. Refer to
DLN-45
.
[P1819] SHIFT ACT CIR  Transfer control device actuator circuit is shorted
or open. (Malfunctions are detected when transfer
shift relay circuit is open/shorted or relay monitor
circuit is open/shorted.)
 Malfunction occurs in transfer control device drive circuit.
 Malfunction is detected in transfer shut off relay. Refer to
DLN-48
.
[P1820] ENGINE SPEED SIG  Malfunction is detected in engine speed signal
that is output from ECM through CAN communi-
cation.
 Improper signal is input while driving. Refer to
DLN-52
.
[P1822] DUTY SOLENOID Proper voltage is not applied to clutch pressure so-
lenoid valve due to open or short circuit. Refer to
DLN-53
.
[P1823] 2-4WD SOLENOID Proper voltage is not applied to 2-4WD solenoid
valve due to open or short circuit. Refer to
DLN-57
.
[P1824] MOTOR RELAY Motor does not operate properly due to open or
short circuit in transfer motor or transfer motor relay.
Refer to
DLN-61
.
Revision: December 20092009 QX56

TRANSFER CONTROL UNITDLN-99
< ECU DIAGNOSIS > [ATX14B]
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DLN
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CAUTION:
 If CAN COMM CIRCUIT [U1000] or CONTROL UNIT (CAN) [U1010] is displayed with other DTCs, first perform the trouble
diagnosis for CAN communication line.
 If ABS OP SIG [P1830], VDC OP SIG [P1831] or TCS OP SIG [P1832] is displayed, first perform the trouble diagnosis for ABS system.
 If VHCL SPEED SEN·AT [P1807] is displayed, firs t perform the trouble diagnosis for A/T system.
NOTE:
 If SHIFT ACT POSI SW [P1818] or SHIFT ACT CIR [P1819] is disp layed, first erase self-diagnostic results. (SHIFT ACT POSI SW
[P1818] or SHIFT ACT CIR [P1819] may be displayed after installing transfer control unit or transfer assembly.)
 If CL PRES SW [P1827] or LINE PRES SW [P1828] is displayed only while driving in reverse, check the continuity of R position o n
transmission range switch. When there is no malfunction found in the electrical system, check the hydraulic system.
FLASH CODE CHART
[P1826] OIL TEMP SEN Signal voltage from transfer fluid temperature sen-
sor is abnormally high (Transfer fluid temperature is
abnormally low) while driving. Refer to
DLN-67.
[P1827] CLUTCH PRES SW  Improper signal from clutch pressure switch is in-
put due to open or short circuit.
 Malfunction occurs in clutch pressure switch or
hydraulic circuit. Refer to
DLN-70
.
[P1828] LINE PRES SW  Improper signal from line pressure switch is input
due to open or short circuit.
 Malfunction occurs in line pressure switch or hy-
draulic circuit. Refer to
DLN-73
.
[P1829] THROTTLE POSI SEN  Malfunction is detected in accelerator pedal posi-
tion signal that is output from ECM through CAN
communication.
 Signal voltage from accelerator pedal position sensor is abnormally high or low. Refer to
DLN-76
.
[P1830] ABS OP SIG Malfunction is detected in ABS operation signal that
is output from ABS actuator and electric unit (control
unit) through CAN communication. Refer to
DLN-77
.
[P1831] VDC OP SIG Malfunction is detected in VDC operation signal that
is output from ABS actuator and electric unit (control
unit) through CAN communication.
Refer to
DLN-78
.
[P1832] TCS OP SIG Malfunction is detected in TCS operation signal that
is output from ABS actuator and electric unit (control
unit) through CAN communication. Refer to
DLN-79
.
[U1010] CONTROL UNIT (CAN) Detecting error during the initial diagnosis of CAN
controller of transfer control unit. Refer to
DLN-80
DTC CONSULT-III Diagnostic item is detected when... Reference
Flashing pattern Item Diagnostic item is detected when... Reference
2 Vehicle speed signal
(from A/T)  Malfunction is detected in output shaft revolution signal
that is output from TCM through CAN communication.
 Improper signal is input while driving. Refer to
DLN-26
.
3 Clutch pressure sole-
noid signal Proper voltage is not applied to clutch pressure solenoid
valve due to open or short circuit.
Refer to
DLN-53
.
4 2-4WD solenoid signal Proper voltage is not applied to 2-4WD solenoid valve due
to open or short circuit.
Refer to
DLN-57
.
5 Transfer motor Transfer motor does not operate properly due to open or
short circuit in transfer motor or transfer motor relay. Refer to
DLN-61
.
6 Vehicle speed signal
(from ABS)  Malfunction is detected in vehicle speed signal that is out-
put from ABS actuator and elec tric unit (control unit)
through CAN communication.
 Improper signal is input while driving. Refer to
DLN-27
.
7 CAN communication Malfunction has been detected from CAN communication
line. Refer to
LAN-51
.
Revision: December 20092009 QX56

DLN-100
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
8 AD converterAD converter system of transfer control unit is malfunction-
ing. Refer to
DLN-24.
9 Transfer fluid tempera-
ture Signal voltage from transfer fluid temperature sensor is ab-
normally high (Transfer fluid temperature is abnormally low)
while driving.
Refer to
DLN-67
.
10 Neutral-4LO switch Improper signal from neutral-4LO switch is input due to
open or short circuit. Refer to
DLN-28
.
11 Clutch pressure switch  Improper signal is input due to open or short circuit.
 Malfunction occurs in clutch pressure switch or hydraulic
circuit. Refer to
DLN-70
.
12 Line pressure switch  Improper signal is input due to open or short circuit.
 Malfunction occurs in line pressure switch or hydraulic
circuit. Refer to
DLN-73
.
13 Engine speed signal
(from ECM)  Malfunction is detected in engine speed signal that is out-
put from ECM through CAN communication.
 Improper signal is input while driving. Refer to
DLN-52
.
14 Accelerator pedal posi-
tion sensor (from
ECM)  Malfunction is detected in accelerator pedal position sig-
nal that is output from ECM through CAN communication.
 Signal voltage from accelerator pedal position sensor is abnormally high or low. Refer to
DLN-76
.
15 Power supply Power supply voltage for transfer control unit is abnormally
low while driving.
Refer to
DLN-22
.
16 4WD shift switch More than two switch inputs are simultaneously detected
due to short circuit of 4WD shift switch. Refer to
DLN-31
.
17 ABS operation signal
(from ABS) Malfunction is detected in ABS operation signal that is out-
put from ABS actuator and electric unit (control unit)
through CAN communication.
Refer to
DLN-77
.
18 Wait detection switch Improper signal from wait detection switch is input due to
open or short circuit. Refer to
DLN-35
.
19 Actuator motor  Motor does not operate properly due to open or short cir-
cuit in actuator motor.
 Malfunction is detected in the actuator motor. (When 4WD shift switch is operated and actuator motor is not
operated)
 Malfunction is detected in transfer shift high relay and transfer shift low relay. Refer to
DLN-39
.
20 Actuator position
switch  Improper signal from actuator position switch is input due
to open or short circuit.
 Malfunction is detected in the actuator position switch. Refer to
DLN-45
.
21 Actuator circuit  Transfer control device actuator circuit is shorted or open.
(Malfunctions are detected when motor relay circuit is
open/shorted or relay transfer shift circuit is open/short-
ed.)
 Malfunction occurs in transfer control device drive circuit. Refer to
DLN-48
.
22 VDC operation signal
(from VDC) Malfunction is detected in VDC operation signal that is out-
put from ABS actuator and electric unit (control unit)
through CAN communication.
Refer to
DLN-78
.
23 TCS operation signal
(from TCS) Malfunction is detected in TCS operation signal that is out-
put from ABS actuator and electric unit (control unit)
through CAN communication.
Refer to
DLN-79
.
24 Transmission range
switch signal (from
TCM) When transmission range switch signal is malfunction or
communication error between the control units.
Refer to
DLN-38
.
Repeats flickering
every 2 to 5 sec. — System normal. Refer to
DLN-102
Flashing pattern Item Diagnostic item is detected when... Reference
Revision: December 20092009 QX56

EC-5
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On Board Diagnosis Logic ..................................
..
295
P1211 TCS CONTROL UNIT ...........................296
Description .......................................................... ..296
On Board Diagnosis Logic ....................................296
DTC Confirmation Procedure ................................296
Diagnosis Procedure .............................................296
P1212 TCS COMMUNICATION LINE ..............297
Description .......................................................... ..297
On Board Diagnosis Logic ....................................297
DTC Confirmation Procedure ................................297
Diagnosis Procedure .............................................297
P1217 ENGINE OVER TEMPERATURE .........298
On Board Diagnosis Logic .................................. ..298
Overall Function Check .........................................298
Diagnosis Procedure .............................................299
Main 13 Causes of Overheating ............................300
P1225 TP SENSOR ..........................................302
Component Description ....................................... ..302
On Board Diagnosis Logic ....................................302
DTC Confirmation Procedure ................................302
Diagnosis Procedure .............................................302
P1226 TP SENSOR ..........................................304
Component Description ....................................... ..304
On Board Diagnosis Logic ....................................304
DTC Confirmation Procedure ................................304
Diagnosis Procedure .............................................304
P1421 COLD START CONTROL .....................306
Description .......................................................... ..306
On Board Diagnosis Logic ....................................306
DTC Confirmation Procedure ................................306
Diagnosis Procedure .............................................306
P1550 BATTERY CURRENT SENSOR ...........308
Component Description ....................................... ..308
On Board Diagnosis Logic ....................................308
DTC Confirmation Procedure ................................308
Diagnosis Procedure .............................................308
Component Inspection ..........................................310
P1551, P1552 BATTERY CURRENT SEN-
SOR ..................................................................
312
Component Description ....................................... ..312
On Board Diagnosis Logic ....................................312
DTC Confirmation Procedure ................................312
Diagnosis Procedure .............................................312
Component Inspection ..........................................314
P1553 BATTERY CURRENT SENSOR ...........316
Component Description ....................................... ..316
On Board Diagnosis Logic ....................................316
DTC Confirmation Procedure ................................316
Diagnosis Procedure .............................................316
Component Inspection ..........................................318
P1554 BATTERY CURRENT SENSOR ...........320
Component Description ....................................... ..320
On Board Diagnosis Logic .....................................320
Overall Function Check .........................................320
Diagnosis Procedure .............................................321
Component Inspection ...........................................322
P1564 ICC STEERING SWITCH .....................324
Component Description .........................................324
On Board Diagnosis Logic .....................................324
DTC Confirmation Procedure ................................324
Diagnosis Procedure .............................................324
Component Inspection ...........................................326
P1564 ASCD STEERING SWITCH .................328
Component Description .........................................328
On Board Diagnosis Logic .....................................328
DTC Confirmation Procedure ................................328
Diagnosis Procedure .............................................328
Component Inspection ...........................................330
P1568 ICC FUNCTION ....................................332
On Board Diagnosis Logic .....................................332
DTC Confirmation Procedure ................................332
Diagnosis Procedure .............................................332
P1572 ICC BRAKE SWITCH ..........................333
Component Description .........................................333
On Board Diagnosis Logic .....................................333
DTC Confirmation Procedure ................................333
Diagnosis Procedure .............................................334
Component Inspection ...........................................337
P1572 ASCD BRAKE SWITCH ......................339
Component Description .........................................339
On Board Diagnosis Logic .....................................339
DTC Confirmation Procedure ................................339
Diagnosis Procedure .............................................340
Component Inspection ...........................................343
P1574 ICC VEHICLE SPEED SENSOR .........344
Component Description .........................................344
On Board Diagnosis Logic .....................................344
DTC Confirmation Procedure ................................344
Diagnosis Procedure .............................................344
P1574 ASCD VEHICLE SPEED SENSOR .....346
Component Description .........................................346
On Board Diagnosis Logic .....................................346
DTC Confirmation Procedure ................................346
Diagnosis Procedure .............................................346
P1805 BRAKE SWITCH .................................348
Description .............................................................348
On Board Diagnosis Logic .....................................348
DTC Confirmation Procedure ................................348
Diagnosis Procedure .............................................348
Component Inspection ...........................................350
P2100, P2103 THROTTLE CONTROL MO-
TOR RELAY ....................................................
351
Component Description .........................................351
Revision: December 20092009 QX56