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Q501 4 Cylinder MT Application
DTC Troubleshooting Data
Version: 0.1
Date: 21-Sep-2018
Prepared By: Mithi Prasad, Sarang Kulkarni, Manish Gupta
Checked By: Yogesh Jadhav
Approved By: Satish Kumar P
Page: 873 of 1052
Copyright ©
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.
P0571-94: Brake Switch “A” Circuit – Brake pedal switch signal incorrect after event (0/1 error)
Overview:
DTC Description (User Friendly)
Brake pedal switch signal incorrect after event (0/1 error)
ECU Pin Number
K035, K010
Customer Symptom
CEL ON, Cruise Control will be disabled
Fault Effects (On Vehicle)
Cruise Control will be disabled
Lamp Status (If Any)
MIL OFF, CEL ON
Fault Detection Condition (Root cause)
EMS ECU receives 0V at pin K010 and 12 V at Pin K035
when Brake Pedal is pressed or released.
Normal Operating Condition
No Fault Code
Probable Trouble Area
WH connections between EMS ECU and Brake Pedal switch
connector.
Brake pedal stuck in grey Zone between two switches.
Healing Condition
Rectify the error
Clear through diagnostic tool
Ignition OFF & ON
Component Details:
For safety reasons, Brake pedal is equipped with two Switches. These switches transition their states when the brake
pedal is pressed. EMS ecu uses the brake press information in its control strategies like Torque demand calculation, Gear
Shift indication, Accelerator pedal stuck detection, vehicle start function when clutch sensor fails etc.
Preliminary Checks:
1. 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.
2. Check whether similar complaints are earlier reported. If yes, perform the preliminary checks with respect to
earlier issue closure.
3. Check for any other faults presence related to ECU Internal power supplies; Follow rectification process for those
faults, before proceeding further.
4.
Check whether the Brake Pedals is moving freely. Else look for Mechanical issues and correct them.
5. Check for Wiring Dis-continuity between Brake Pedal Switch & EMS ECU. If found, fix them
6. Check whether the Main Brake switch is stuck open
7. Check whether the redundant brake switch is stuck open.
Trouble Shooting:
Step Checks
IF YES
IF NO
1.
Check for any other faults presence related to ECU Internal
power supplies / Accelerator pedal sensor / Brake Pedal
Sensor.
Follow rectification
process for the
faults, before
proceeding further
Go to Step 2
2
Check for electrical continuity between ECU to Brake Pedal
sensor connector as per the circuit schematic. Continuity
exists?
Go to next step
Establish continuity
by rectifying
harness