1695 / 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: 484 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.
P0481: Fan 2 Control Circuit - Open
Overview:
DTC Description as per ISO standard
Fan 2 Control Circuit
ECU Pin Number
79
Customer Symptom
AC compressor will not be engaged even if AC is requested.
Cooling fans will not run in low speed.
Engine over temperature warning lamp will turn on at lesser engine
coolant temperature (8 degrees less than normal condition).
Fault Effects (On Vehicle)
Radiator fan will remain run continuously.
SPCS injector learning will be disabled.
Threshold for Engine over temperature warning lamp turn ON will
be reduced.
Lamp Status (If Any)
CE lamp is on
Fault Detection Condition
This DTC is logged due to open circuit of EMS ecu high speed fan
drive pin.
Normal Operating Condition
No faults related to high speed fan control circuit.
Probable Trouble Area
High Speed fan relays, EMS ecu, Wiring harness connections
between relay and EMS, Relay and its power supply and ground.
Healing Condition
Clear the errors, Ignition OFF to ON, engine idle & fly-up condition
Component Details:
Cooling Fan circuit consists of two fans. With the help of Relays, cooling fans will be made to run either in Series (Low
Speed) or Parallel (High Speed). EMS will decide whether to turn the cooling fans in low speed or high speed based on
Engine coolant temperature & AC refrigerant pressure.
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
Loose/ Damaged Connections between high speed fan Relay 1 / 2 and EMS ecu.
x
Loose/ Damaged Connections between High speed fan Relay 1 / 2 and Battery supply or Ground.
x
Check for back out of pins & damage of pins at ECU connector.