1644 / 5157
OSPREY- Application
DTC Troubleshooting Data
Version: 4.0
Date: 10-02-2017
Prepared by: Mithipati Prasad
Checked by: G S Raju / Senthilnathan S
Page: 433 of 654
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.
P1571: Brake safety switch fault
Overview:
Description as per ISO standard
Brake safety switch fault
Customer Symptom
No Critical effect
ECU PIN No
13
Fault Effects (On Vehicle)
No Critical effect
Lamp Status (If Any)
-
Fault Detection Condition
This fault gets logged if EMS detects transitions in Brake Light switch /
Brake main switch input but not in Brake safety switch / Brake
redundant switch input.
Normal Operating Condition
EMS ECU finds coherence between Brake Switch inputs.
Probable Trouble Area
Wiring harness Connections between Brake Safety / redundant Switch
and EMS ECU, Improper Brake Switch Setting, Brake safety switch,
EMS ECU
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:
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 whether the Brake Safety Switch is either stuck open or closed.
x
Check, if the Brake lights are on even when no brake pedal is pressed.
x
Loose/ Damaged Connections between Brake Switch connector and EMS ECU.
x
Check for back out / damage of pins at ECU connector.
x
Check for back out / damage of pins at Brake switch connector.
x
Check for any physical damage of EMS ecu / Brake switches connectors.