2003 NISSAN TEANA light

DTC P1574 ASCD VEHICLE SPEED SENSOR
EC-611
[VQ]
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EC

DTC P1574 ASCD VEHICLE SPEED SENSORPFP:31036
Component DescriptionBBS0053U
The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from “unified
meter and A/C amp.” and the other is from TCM (Transmission control module). The ECM uses these signals
for ASCD control. Refer to EC-363, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for ASCD functions.
On Board Diagnosis LogicBBS0053V
This self-diagnosis has the one trip detection logic.
The MI will not light up for this diagnosis.
NOTE:

If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-458, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-538, "
DTC P0605 ECM"
DTC Confirmation ProcedureBBS0053W
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Step 3 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25 MPH).
4. If DTC is detected, go to EC-612, "
Diagnostic Procedure" .
WITHOUT CONSULT-II
TESTING CONDITION:
Step 2 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
1. Start engine.
2. Drive the vehicle at more than 40 km/h (25 MPH).
3. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
4. Perform Diagnostic Test Mode II (Self-diagnostic results) with ECM.
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1574
1574ASCD vehicle speed
sensorECM detects a difference between two vehicle
speed signals is out of the specified range.

Harness or connectors
(The CAN communication line is open or
shorted.)

Unified meter and A/C amp.

ABS actuator and electric unit (control unit)

Wheel sensor

TCM

ECM
SEF058Y

EC-622
[VQ]
DTC P1715 INPUT SPEED SENSOR (PRIMARY SPEED SENSOR)

DTC P1715 INPUT SPEED SENSOR (PRIMARY SPEED SENSOR)PFP:31935
DescriptionBBS005AZ
ECM receives primary speed sensor signal from TCM through CAN communication line.
CONSULT-II Reference Value in Data Monitor ModeBBS005B0
Specification data are reference values.
On Board Diagnosis LogicBBS005B1
NOTE:

If DTC P1715 is displayed with DTC U1000 or U1001 first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-458, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P1715 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-538, "
DTC P0605 ECM" .

If DTC P1715 is displayed with DTC P0335, first perform the trouble diagnosis for DTC P0335.
Refer to EC-517, "
DTC P0335 CKP SENSOR (POS)" .

If DTC P1715 is displayed with DTC P0340 or P0345, first perform the trouble diagnosis for DTC
P0340, P0345. Refer to EC-524, "
DTC P0340, P0345 CMP SENSOR (PHASE)" .
The MI will not light up for this diagnosis.
DTC Confirmation ProcedureBBS005B2
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine.
4. Drive vehicle at a speed of more than 50 km/h (31 MPH) for at
least 5 seconds.
5. If 1st trip DTC is detected, go to EC-623, "
Diagnostic Procedure"
.
MONITOR ITEM CONDITION SPECIFICATION
I/P PULLY SPD

Vehicle speed: More than 20 km/h (12MPH)Almost the same speed as the
tachometer indication
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1715
1715Input speed sensor
(Primary speed sensor)
(TCM output)Primary speed sensor signal is different
from the theoretical value calculated by
ECM from secondary speed sensor sig-
nal and engine rpm signal.

Harness or connectors
(The CAN communication line is open or
shorted)

Harness or connectors
(Primary speed sensor circuit is open or
shorted)

TCM
SEF058Y

EC-624
[VQ]
DTC P1720 VSS

DTC P1720 VSSPFP:31036
DescriptionBBS005B3
NOTE:
If DTC P1720 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-458, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
ECM receives two vehicle speed signals via CAN communication line. One is sent from “ABS actuator and
electric unit (control unit)” via “unified meter and A/C amp.”, and the other is from TCM (Transmission control
module). ECM uses these signals for engine control.
CONSULT-II Reference Value in Data Monitor ModeBBS005B4
Specification data are reference values.
On Board Diagnosis LogicBBS005B5
The MI will not light up for this self-diagnosis.
DTC Confirmation ProcedureBBS005B6
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine.
4. Drive vehicle at a speed of 20 km/h (12 MPH) or more for at
least 5 seconds without brake pedal depressing.
5. If 1st trip DTC is detected, go to EC-625, "
Diagnostic Procedure"
.
MONITOR ITEM CONDITION SPECIFICATION
VHCL SPEED SE

Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1720
1720Vehicle speed sensor
(TCM output)A difference between two vehicle speed sig-
nals is out of the specified range.

Harness or connectors
(Secondary speed sensor circuit is open or
shorted)

Harness or connectors
(Wheel sensor circuit is open or shorted.)

TCM

Secondary speed sensor

ABS actuator and electric unit (control unit)

Wheel sensor

Unified meter and A/C amp.
PBIB2673E

EC-626
[VQ]
DTC P1805 BRAKE SWITCH

DTC P1805 BRAKE SWITCHPFP:25320
DescriptionBBS00544
Brake switch signal is applied to the ECM through the stop lamp switch when the brake pedal is depressed.
This signal is used mainly to decrease the engine speed when the vehicle is driving.
CONSULT-II Reference Value in Data Monitor ModeBBS00545
Specification data are reference values.
On Board Diagnosis LogicBBS00546
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
DTC Confirmation ProcedureBBS00547
WITH CONSULT-II
1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the DTC with CONSULT-II.
4. Select “DATA MONITOR” mode with CONSULT-II.
5. If 1st trip DTC is detected, go to EC-628, "
Diagnostic Procedure"
.
WITHOUT CONSULT-II
1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the Diagnostic Test Mode II (Self-diagnostic results) memory. Refer to EC-378, "
How to Set Diag-
nostic Test Mode II (Self-diagnostic Results)" .
4. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
5. Perform Diagnostic Test Mode II (Self-diagnostic results) with ECM.
6. If DTC is detected, go to EC-628, "
Diagnostic Procedure" .
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW

Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1805
1805Brake switchA brake switch signal is not sent to ECM for
extremely long time while the vehicle is driving.

Harness or connectors
(Stop lamp switch circuit is open or
shorted.)

Stop lamp switch
Engine operating condition in fail-safe mode
ECM controls the electric throttle control actuator by regulating the throttle opening to a small range.
Therefore, acceleration will be poor.
Vehicle condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration
SEF058Y

EC-628
[VQ]
DTC P1805 BRAKE SWITCH

Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureBBS00549
1. CHECK STOP LAMP SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Check the stop lamp when depressing and releasing the brake pedal.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Disconnect stop lamp switch harness connector.
2. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
101 R/G Stop lamp switch[Ignition switch: OFF]

Brake pedal: Fully releasedApproximately 0V
[Ignition switch: OFF]

Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
Brake pedal Stop lamp
Fully released Not illuminated
Slightly depressed Illuminated
PBIB2469E
Voltage: Battery voltage
PBIB2102E

EC-630
[VQ]
DTC P1805 BRAKE SWITCH

Component InspectionBBS0054A
STOP LAMP SWITCH
1. Disconnect stop lamp switch harness connector.
2. Check continuity between stop lamp switch terminals 3 and 4
under the following conditions.
3. If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 2 again.
PBIB2469E
Conditions Continuity
Brake pedal: Fully released Should not exist
Brake pedal: Slightly depressed Should exist
PBIB2103E

DTC P2122, P2123 APP SENSOR
EC-631
[VQ]
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EC

DTC P2122, P2123 APP SENSORPFP:18002
Component DescriptionBBS0054B
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-II Reference Value in Data Monitor ModeBBS0054C
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differ from ECM terminal voltage.
On Board Diagnosis LogicBBS0054D
These self-diagnoses have the one trip detection logic.
NOTE:
If DTC P2122 or P2123 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229.
Refer to EC-590, "
DTC P1229 SENSOR POWER SUPPLY" .
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MI lights up.
PBIB1741E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN 1

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.65 - 0.87V
Accelerator pedal: Fully depressed More than 4.3V
ACCEL SEN 2*

Ignition switch ON
(Engine stopped)Accelerator pedal: Fully released 0.56 - 0.96V
Accelerator pedal: Fully depressed More than 4.0V
CLSD THL POS

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2122
2122Accelerator pedal posi-
tion sensor 1 circuit low
inputAn excessively low voltage from the APP sen-
sor 1 is sent to ECM.

Harness or connectors
(APP sensor 1 circuit is open or
shorted.)

Accelerator pedal position sensor
(APP sensor 1) P2123
2123Accelerator pedal posi-
tion sensor 1 circuit high
inputAn excessively high voltage from the APP sen-
sor 1 is sent to ECM.
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.

EC-638
[VQ]
DTC P2127, P2128 APP SENSOR

DTC P2127, P2128 APP SENSORPFP:18002
Component DescriptionBBS0054J
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-II Reference Value in Data Monitor ModeBBS0054K
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differ from ECM terminal voltage.
On Board Diagnosis LogicBBS0054L
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MI lights up.
PBIB1741E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN 1

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.65 - 0.87V
Accelerator pedal: Fully depressed More than 4.3V
ACCEL SEN 2*

Ignition switch ON
(Engine stopped)Accelerator pedal: Fully released 0.56 - 0.96V
Accelerator pedal: Fully depressed More than 4.0V
CLSD THL POS

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2127
2127Accelerator pedal posi-
tion sensor 2 circuit low
inputAn excessively low voltage from the APP sen-
sor 2 is sent to ECM.

Harness or connectors
(APP sensor 2 circuit is open or
shorted.)
(TP sensor circuit is shorted.)

Accelerator pedal position sensor
(APP sensor 2)

Electric throttle control actuator
(TP sensor 1 and 2) P2128
2128Accelerator pedal posi-
tion sensor 2 circuit high
inputAn excessively high voltage from the APP sen-
sor 2 is sent to ECM.
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.