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OSPREY- Application
DTC Troubleshooting Data
Version: 4.0
Date: 10-02-2017
Prepared by: Mithipati Prasad
Checked by: G S Raju / Senthilnathan S
Page: 131 of 654
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TATA MOTORS Ltd.
This document must not be used in any way, such as copying and redistributing to third parties, without the consent of author.
P0120: Accelerator Pedal Sensor Fault
Overview:
DTC Description as per ISO standard
Throttle/Pedal Position Sensor/Switch “A”
Circuit
ECU Pin Number
37
Customer Symptom
No response from Accelerator Pedal.
Engine Speed will be slightly increased to ~1300 RPM for
mobility of vehicle.
Fault Effects (On Vehicle)
Limp Home Mode gets activated.
Lamp Status (If Any)
CE Lamp is on
Fault Detection Condition
This DTC gets logged if both track 1 and Track 2 signal are
out
of
range / failed ( e.g. Pedal connector is removed from the
pedal)
Normal Operating Condition
Diagnostic tool display the value of accelerator pedal pressed
in % at ignition ON condition
Probable Trouble Area
Accelerator Pedal sensor
Related wiring Harness, connector or terminals
ECU
Healing Condition
Rectify the error
Clear through diagnostic tool
Ignition OFF & ON
Component Details:
For safety reasons, the accelerator pedal sensor is equipped with 2 resistors (potentiometers) with varying operating
ranges (0.75
–
4.45 V and 0.38
–
2.23 V) and separate circuits. A potentiometer informally a pot, is a three- terminal
resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used, one end and the
wiper, it acts as a variable resistor or rheostat. Based on the Accelerator pedal position, Engine will produce the driver
demanded torque based on the accelerator pedal position.
Preliminary Checks:
x
Check whether the customer voice / view about the issue is matching with the fault effects mentioned above. If
yes, go ahead with next steps. If not, check for other DTC’s presence.
x
Check whether similar complaints are earlier reported. If yes, perform the preliminary checks with respect to
earlier issue closure.
x
Check for Reference voltage 2 fault (P0642, P0643) if present; Follow Reference voltage2(sensor supply
voltage2) check and rectification Procedure, to correct this fault before proceeding further
x
Check the pedal connector connected to the pedal sensor/ module.
x
Check sensor connections for rust dirt etc; clean the sensor connections and ensure proper fitment.
x
Check Intermediate connector; Remove Intermediate connector between EMS harness and vehicle wiring
harness. Check for terminal back out. Do necessary repairs, then reconnect and check the fault.
x
Visually check sensor; Replace sensor if damaged.