DTC P2138 APP SENSOR
DTC P2138 APP SENSOR PFP:18002
Component Description UBS00NMK
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.
PBIB1741E
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 Mode UBS00NML
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
● Ignition switch: ON Accelerator pedal: Fully released 0.5 - 1.0V
ACCEL SEN 1
(Engine stopped) Accelerator pedal: Fully depressed 4.2 - 4.8V
● Ignition switch: ON Accelerator pedal: Fully released 0.5 - 1.0V
ACCEL SEN 2*
(Engine stopped) Accelerator pedal: Fully depressed 4.2 - 4.8V
● Ignition switch: ON Accelerator pedal: Fully released ON
CLSD THL POS
(Engine stopped) Accelerator pedal: Slightly depressed OFF
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differ from ECM terminal voltage.
On Board Diagnosis Logic UBS00NMM
This self-diagnosis has the one trip detection logic.
NOTE:
If DTC P2138 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to
EC-466, "DTC P0643 SENSOR POWER SUPPLY" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
● Harness or connector
(APP sensor 1 and 2 circuit is open or
Accelerator pedal position Rationally incorrect voltage is sent to ECM shorted.)
P2138 (TP sensor circuit is shorted.)
sensor circuit range/per- compared with the signals from APP sensor 1
2138
formance and APP sensor 2. ● Accelerator pedal position sensor 1 and 2
● Electric throttle control actuator
(TP sensor)
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
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.
Revision: July 2005 EC-562 2006 Titan
DTC P2138 APP SENSOR
DTC Confirmation Procedure UBS00NMN
A
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: EC
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
WITH CONSULT-II
1. Turn ignition switch ON. C
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
D
4. If DTC is detected, go to EC-565, "Diagnostic Procedure" .
SEF058Y
WITH GST G
Follow the procedure “WITH CONSULT-II” above.
Revision: July 2005 EC-563 2006 Titan
DTC P2138 APP SENSOR
Wiring Diagram UBS00NMO
BBWA1709E
Revision: July 2005 EC-564 2006 Titan
DTC P2138 APP SENSOR
Specification data are reference values and are measured between each terminal and ground.
CAUTION: A
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.
TER- EC
WIRE
MINAL ITEM CONDITION DATA (DC Voltage)
COLOR
NO.
Sensor power supply C
47 Y [Ignition switch: ON] Approximately 5V
(TP sensor)
[Engine is running]
Sensor ground
82 B/R ● Warm-up condition Approximately 0V D
(APP sensor 1)
● Idle speed
[Engine is running]
Sensor ground
83 G/W ● Warm-up condition Approximately 0V E
(APP sensor 2)
● Idle speed
Sensor power supply
90 L [Ignition switch: ON] Approximately 5V
(APP sensor 1) F
Sensor power supply
91 W/R [Ignition switch: ON] Approximately 5V
(APP sensor 2)
[Ignition switch: ON] G
● Engine: Stopped 0.25 - 0.50V
Accelerator pedal position ● Accelerator pedal: Fully released
98 G/R H
sensor 2 [Ignition switch: ON]
● Engine: Stopped 2.0 - 2.5V
● Accelerator pedal: Fully depressed
I
[Ignition switch: ON]
● Engine: Stopped 0.5 - 1.0V
Accelerator pedal position ● Accelerator pedal: Fully released
106 BR/W J
sensor 1 [Ignition switch: ON]
● Engine: Stopped 4.2 - 4.8V
● Accelerator pedal: Fully depressed K
Diagnostic Procedure UBS00NMP
1. CHECK GROUND CONNECTIONS L
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-156, "Ground Inspection" . M
BBIA0354E
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
Revision: July 2005 EC-565 2006 Titan
DTC P2138 APP SENSOR
2. CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness
connector.
2. Turn ignition switch ON.
BBIA0361E
3. Check voltage between APP sensor terminal 7 and ground with
CONSULT-II or tester.
Voltage: Approximately 5V
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
PBIB2070E
3. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ON.
2. Check voltage between APP sensor terminal 6 and ground with
CONSULT-II or tester.
Voltage: Approximately 5V
OK or NG
OK >> GO TO 8.
NG >> GO TO 4.
PBIB2069E
4. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between APP sensor terminal 6 and ECM terminal 91.
Refer to Wiring Diagram.
Continuity should exist.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit in harness or connectors.
Revision: July 2005 EC-566 2006 Titan
DTC P2138 APP SENSOR
5. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-III A
Check harness for short to power and short to ground, between the following terminals
ECM terminal Sensor terminal Reference Wiring Diagram
EC
47 Electric throttle control actuator terminal 2 EC-557
91 APP sensor terminal 6 EC-564
OK or NG C
OK >> GO TO 6.
NG >> Repair short to ground or short to power in harness connectors.
D
6. CHECK THROTTLE POSITION SENSOR
Refer to EC-569, "Component Inspection" .
E
OK or NG
OK >> GO TO 12.
NG >> GO TO 7.
F
7. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator. G
2. Perform EC-83, "Throttle Valve Closed Position Learning" .
3. Perform EC-85, "Idle Air Volume Learning" .
H
>> INSPECTION END
8. CHECK APP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector. J
3. Check harness continuity between ECM terminal 82 and APP sensor terminal 1, ECM terminal 83 and
APP sensor terminal 3.
Refer to Wiring Diagram. K
Continuity should exist.
4. Also check harness for short to ground and short to power.
L
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
M
9. CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 106 and APP sensor terminal 2, ECM terminal 98 and
APP sensor terminal 5.
Refer to Wiring Diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
Revision: July 2005 EC-567 2006 Titan
DTC P2138 APP SENSOR
10. CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-569, "Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-83, "Accelerator Pedal Released Position Learning" .
3. Perform EC-83, "Throttle Valve Closed Position Learning" .
4. Perform EC-85, "Idle Air Volume Learning" .
>> INSPECTION END
12. CHECK INTERMITTENT INCIDENT
Refer to EC-150, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Revision: July 2005 EC-568 2006 Titan
DTC P2138 APP SENSOR
Component Inspection UBS00NMQ
ACCELERATOR PEDAL POSITION SENSOR A
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Check voltage between ECM terminals 106 (APP sensor 1 sig- EC
nal), 98 (APP sensor 2 signal) and ground under the following
conditions.
C
Terminal Accelerator pedal Voltage
106 Fully released 0.5 - 1.0V
(Accelerator pedal position
sensor 1) Fully depressed 4.2 - 4.8V D
98 Fully released 0.25 - 0.5V
(Accelerator pedal position
sensor 2) Fully depressed 2.0 - 2.5V E
MBIB0023E
4. If NG, replace accelerator pedal assembly and go to next step.
5. Perform EC-83, "Accelerator Pedal Released Position Learning" .
F
6. Perform EC-83, "Throttle Valve Closed Position Learning" .
7. Perform EC-85, "Idle Air Volume Learning" .
Removal and Installation UBS00NMR G
ACCELERATOR PEDAL
Refer to ACC-3, "ACCELERATOR CONTROL SYSTEM" .
H
Revision: July 2005 EC-569 2006 Titan
