ARIA

ENGINE

171

RESITANCE VS TEMPERATURE CHART

Measure resistance between Pin no. 3 & 4 at various

temperature given in below table.

T [°C] Rnom [

Ω

]

Tolerance

Rmin [

Ω

]

Tolerance

Rmax [

Ω

]

-10

9202

8716

9689

5774

5497

6050

3714

3553

3875

2448

2353

2544

315.8

310.0

321.6

100

182.8

180.4

185.1

REFITMENT

1. Locate the TMAP sensor on intercooler outlet and

fit one mounting bolt.

2. Connect the electrical connection to the TMAP

sensor.

4. SIMAF SENSOR (

Siemens Integrated Mass

Airflow Sensor

)

This sensor gives Information about the amount of

air quantity and temperature of the air entering in the

engine. This input is used by the ECU for corrections

of fuel quantity based on amount of air availability for

optimization of exhaust gas circulation & the turbo-

charger control.

NOTE

While assembling, the AMF sensor the point of the

arrow should be towards the Turbo charger.

The operating principle is based on the heating of a

diaphragm (

sensitive

element

containing

two

re-

sistances upstream and downstream of the support

)

in a by-pass duct through which the engine intake air

flows.

Two temperature dependent metal film resistors on

thin glass substrates are mounted in the SIMAF flow

channel. The resistors are connected with fixed re-

sistors R1 and R2 in a bridge circuit. The bridge is

balanced so that the control electronics heat RS to a

fixed temperature differential relative to the intake

air. The sensing resistor RT compensates for intake

air temperature variations, holding the constant tem-

perature offset of RS. The intake airflow converts

heat from RS and the heating current must be dy-

namically increased by the control electronics to

maintain the fixed offset temperature. The current

flowing through RS is a measure for the mass airflow

and can be measured as a voltage drop across the

fixed resistor R2. This signal is processed by the

sensor and is output as either an analog or frequen-

cy signal.

NOTE

The flow meter measures the air mass directly (not

the volume) to eliminate problems of compensation

correlated to the temperature, altitude, pressure val-

ues etc

LOCATION:

This sensor is mounted between air

filter and turbocharger.