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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: 685 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.
P0100-11: Mass or Volume Air Flow Sensor “A” Circuit – SCG of hardware signal of HFM sensor
Overview:
DTC Description (User Friendly)
SCG of hardware signal of HFM6 sensor
ECU Pin Number
K086
Customer Symptom
MIL ON
Fault Effects (On Vehicle)
-
Lamp Status (If Any)
MIL ON.
MIL OFF: After 3 warm up Cycles (Drive Cycle with coolant
temperature increase by 22 degrees) or Clear DTC Command
with fault condition no more present.
Fault Detection Condition (Root cause)
Short circuit to ground error on signal line
Normal Operating Condition
No Fault Code
Probable Trouble Area
AMF - Air Mass Flow Temperature sensor (HFM)
Related wiring Harness, connector or terminals,
ECU
Healing Condition
Rectify the error
Clear through diagnostic tool
Ignition OFF & ON
Component Details:
The operating principle is based on the heating of a diaphragm (sensitive element
containing two resistances upstream and downstream of the support) in a by-pass duct through which the engine intake
air flows. The hot film membrane is maintained at constant temperature (about 120 °C higher than the incoming air
temperature) by the specific heating resistance controlled by the management electronics. The mass of air passing
through the by-pass duct, giving off heat to the membrane, thermally unbalances the two resistances to an extent directly
proportional to the mass of the incoming fluid, an imbalance that is translated through the control circuit into a resistance
variation, electronically processed and translated into a frequency value to be sent to the engine management control unit.
The imbalance in the resistance value also makes it possible to determine the direction of the column of air. As far as the
air temperature information is concerned, it is sent to the engine management control unit via a dedicated pin in the form
of a duty cycle signal (rectangular wave). The value of the duty is proportional to the value of the temperature.
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. Check for any other faults presence related to ECU Internal power supplies; Follow rectification process for those
faults, before proceeding further.
4. Check for electrical continuity between ECU to AMF connector as per circuit schematic and rectify electrical
discontinuity if noticed.
5. Check inlet air circuit for clogging; wrong assembly/fitment etc; Clean the inlet air circuit and remove any clogging.