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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: 855 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.
P0484-4B: Fan Circuit current High – Cooling Fan 1 (over temperature)
Overview:
DTC Description (User Friendly)
Cooling Fan 1 (over temperature)
ECU Pin Number
K037
Customer Symptom
MIL ON, Cooling Fans operate only in High speed.
Fault Effects (On Vehicle)
Cooling Fans operate only in High Speed
Lamp Status (If Any)
MIL ON
Fault Detection Condition (Root cause)
The hardware detects over temperature on the PWM output
power stage for the Fan actuator – K037.
Normal Operating Condition
No Fault
Probable Trouble Area
Check, whether there is dis-continuity in wiring harness
between Low Speed fan Relay and EMS ECU.
Low Speed fan relay faulty,
EMS ECU faulty
Healing Condition
Rectify the error
Clear through diagnostic tool
Ignition OFF & ON
Component Details:
Cooling Fan circuit consists of a single fan. With the help of Relays and Resistor (to drop the input
power available to Fan for operating it in low speed), cooling fan will be made to run either in Low Speed or 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 (based on Trinary pressure switch inputs).
Preliminary Checks:
1. Check whether the customer voice / view about the issue is matching with the fault effects mentioned in above
Table. If yes, go ahead with next steps. If not, check for other DTC’s presence.
2. Check whether other customers report similar complaints earlier. If yes, perform the preliminary checks with
respect to earlier issue closure.\
3. Loose/ Damaged Connections between low speed fan Relay and EMS ECU.
4. Loose/ Damaged Connections between low speed fan Relay and Battery supply or Ground.
5. Check for proper installation of low speed fan relay in fuse box.
6. Check for damage of pins at ECU connector.
Trouble Shooting:
Step Checks
IF YES
IF NO
1
Check Whether the low speed fan relay is installed on
Vehicle
Go to Next Step
Fit Fan Low speed
Relay
2
Check for any mechanical damage in low speed fan Relay
Replace faulty Relay Go to next step
3
Is there wiring harness electrical continuity between ECU
pin K037 & AC relay pin
3
. Also, Check continuity between
the Main Relay supply and the low speed fan relay pin
1
.
Also check continuity from low speed fan Relay pin
1
to
GND.
Go to next step
Rectify the wiring
harness
connections as per
the circuit
schematic.
4
Are there any pins damaged at EMS ECU Connector
Replace the
Go to Next Step