NEXON DIAGNOSTIC MANUAL

OSPREY- Application

DTC Troubleshooting Data

Version: 4.0

Date: 10-02-2017

Prepared by: Mithipati Prasad

Checked by: G S Raju / Senthilnathan S

Page: 89 of 654

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.

P0104: AMF sensor electrical fault –Gradient

Overview:

DTC Description as per ISO standard

Mass Or Volume Air Flow “A” Circuit Intermittent

ECU Pin Number

Customer Symptom

Fault Effects (On Vehicle)

No recovery action

Probable loss of power and black smoke

This DTC will also cause P1101 to get registered

Lamp Status (If Any)

CE lamp ON because of P1101

Fault Detection Condition (Root cause)

This DTC gets logged if the rate of change of air mass flow is

greater than a calibratable threshold (2000 g/sec2)

Normal Operating Condition

No Faults related to air mass flow / HFM sensor.

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:

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 presenc

Check whether similar complaints are earlier reported. If yes, perform the preliminary checks with respect to

earlier issue closure.

Check for faults P 0101, P0102; P0103; P0104, P0642, P0643; Follow rectification process for the faults, before

proceeding further.

Check inlet air circuit for clogging; wrong assembly/fitment etc; Clean the inlet air circuit and remove any

clogging.