1288 / 1575
SAFARI 400NM
SR
NO
DTC
FTB
DESCRIPTION
CAUSES
EFFECT ON VEHICLE
CHECK
POINTS
CORRECTIVE ACTION
MIL
STATUS
CEL
a.
If all of them log both set (U0101 / U1022 / U1026) and
(U0100 / U1026 / U1027) as Active DTC; then there is an open
circuit in EMS stub (or connector).
b.
Check CAN wiring harness for open circuit failure in EMS
stub (or connector).
c.
Repair or replace CAN wiring harness.
3.
Measure resistance between CAN High (3 pole connector pin
no.3) and CAN Low (3 pole connector pin no.1) lines to detect
open circuit failure in main CAN bus.
4.
Check DTCs in ABS/ESP.
a.
If ABS/ESP logs C1601 as Active DTC; then there is a
permanent Soft Ware failure in ABS/ESP.
b.
Replace ABS/ESP ECU.
5.
Check proper connectivity of CAN High (Pin No.B48) and CAN
Low (Pin No.B47) lines in EMS ECU connector.
120
P0504
62
Signal Compare Failure
This fault gets logged if ECU observes
lack of correlation between main brake
switch input and redundant brake
switch/brake safety switch.
EMS ECU takes following recovery
actions:~
1.
Disables cruise control function.
2.
Disables dTI iso leak test, DTI iso
IMV test & DTI HPV iso test.
1.
Check 15A fuse connected to ignition relay is not blown off and
also check 10A fuse connected to ignition power supply is not
blown off. Replace if found faulty.
2.
Check, if the Brake lights are on even when no brake pedal is
pressed.
3.
Check the brake switch setting (First cruise switch to be
activated and next brake light switch); If the problem is with the
brake setting perform the necessary repairs.
4.
Check Electrical continuity between ECU pins B32 & B30 to
brake pedal connector as per circuit schematics; Check ECU
pins and connector pins for damage/rust. In case of rust then
clean them and refit the connector.
5.
Check whether either EMS ECU pins B32/B30 are short
circuited to battery or ground. If so, then rectify wiring harness
connections according to circuit schematics.
6.
Check and replace ECU still problem persists.
7.
After rectification ensure the following checks for main brake
and redundant brake switches before handing over the vehicle
to customer.~
A) when pedal is not pressed - Respective switch parameter
in tata diagnostic tool should be less than 5%.~
B) when the pedal is fully pressed - Respective switch
parameter in tata diagnostic tool should be more than 95 %.
C) Ensure brake light is not glowing when the brake pedal is
not pressed.
OFF
ON