TIAGO

TIAGO AMT Gasoline

DTC Troubleshooting Guide

Version: 2.0

Date: 06-06-2016

Author: Sathi/Anupama

Page: 119 of 424

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.

36.

P2903 -02: Accelerator Pedal Position Signal not valid

Overview:

ISO Code

P2903-02

Customer Symptom

Automatic gear shift disabled, no gearshift.

Fault Effects (On Vehicle)

Automatic gear shift disabled, (creep will active)

No gearshift.

Lamp Status (If Any)

Transmission Fault Lamp OFF

Fault Detection Condition

This fault gets detected after Ignition On if EMS signals the

TCU that accelerator pedal information on CAN is invalid.

Normal Operating Condition

EMS signals the TCU that accelerator pedal information on

CAN is valid

Probable Trouble Area

Wiring Harness Connections / EMS / TCU

Healing Condition

200 milliseconds after valid sensor signal

Component Details:

Accelerator pedal position signal is transmitted via CAN bus to the TCU.

Preliminary Checks:

1) Loose/ Damaged Accelerator pedal sensor Connections.

2) Check for damage or back out of pins at EMS connector and TCU connector.

3) Check correct fitment of ground cable connections on vehicle chassis.

Trouble Shooting:-

Step Checks

IF YES

IF NO

Is there any rust/oxidation observed on EMS

or TCU connectors?

Clean the Rust or repair or

replace

Go to Step 2

Diagnose the Accelerator pedal input to EMS

(Refer EMS service manual), is there a

problem with accelerator pedal sensor or

sensor to EMS connection?

Ensure correct connection

of accelerator pedal sensor

input to EMS as per EMS

service manual.

Go to step 3

Is TCU power connections on TCU

connector pins 5, 1, 3? Specifically check

Ignition supply toggling with key on/off.

Go to Step 4

Check and rectify harness

power connections.

Connect the EMS diagnostic tool and check

the value of accelerator pedal position with

pressed and unpressed pedal, are correct

values observed?

Replace the TCU

Go to Step 5

Fault Still Persists?

Recheck the above steps

Follow the steps again for

reconfirmation

the following points by referring TCU parameters using TML diagnostic tool

before handing over to customer.

After key and engine ON with TML TCU diagnostic tool connected, monitor the accelerator pedal and confirm that it

changes from about 0% un-pressed to about 100% when pressed fully.

Drive the vehicle through all gears in both Automatic and Manual modes and