MAF Sensor???

[robbo71]

Hi All..It appears my search function on this site is being friendly so appologies up front if this is a duplicate thread to one that had already been started.
How can I check my MAF sensor at home as it has been suggested it might be the source of my high idle when hot issue that I have posted on this forum..

Thanks in advance.

[Bob]

I am fairly sure that the Manuals that you can download here have the voltages that the MAF Sensor puts out.
I am also sure that YNOT posted these voltages somewhere on this Forum

[Bigrig]

This is Tony's original information:


ZD30 Prior series 4
there should be 4 wires at your MAF they'll be Red, White, Black and White terminal 1,2,3 and 4 respectively,
With the car idling, warmed up to normal operating temp, vehicle in nuetral and the AC off test the following;
The 1 (R) should be reading between 1.6 and 2 volts
The 3 (B) should be reading 0v
With the car stopped but the ignition 'on' disconnect the MAF plug and test
The 2 (w) should be reading approx 5v
The 4 (W) should be reading the battery voltage.
If they read these voltages your MAF is fuctioning correctly.

ZD30 Series 4
there should be a 6 pin connector Nothing, White, Black, Red, White and Black, terminal 1,2,3,4,5,&6
With the car idling, warmed up to normal operating temp AC off, in neutral no load test the following
The 3 (B) should be reading 0v
The 4 (R) should be reading between 1.5 to 1.9v at idle increasing to 4.0v when revving through to 4000rpm
With the car stopped but the ignition 'on' disconnect the MAF plug and test
The 2 (W) should be reading the battery voltage
If they read these you MAF is fuctioning

TB45
There should be a Black/Red wire, Black and White wire Term 2,3 &4
With the car idling, warmed up in nuetral and ac off there should be the following
The 3 (B) should be reading 0v
The 4 (W) should be reading 1.3 to 1.8v, and with the engine at 2500rpm should be 2.1 to 2.5v
With the car of disconnect the MAF plug turn the ignition on and test
The 2 (B/R) should be reading the battery voltage

TB48
There should be a White/Green, Yellow, Black/White and Black/Red Term 1,2,3 & 4
With the car idling, warmed up, in nuetral and the AC off there should be the following
The 1 (W/G) should be reading 1.1 to 1.5v, and at 2500rpm 1.7 to 2.4v
The 3 (B/W) should be reading 0v

Turn the car off and disconnect the MAF plug and turn the ignition on
The 2 (Y) should be reading approx 5v
The 4 (B/R) should be reading the battery voltage

RD28
There should be White, Black and Red Term 1,2 &3
With the car idling warmed up in nuetral with the AC off there should be the following
The 2 (B) Should be reading 0v
The 3 (R) should be reading 1.6 to 2.0v

Withe the car off disconnect the MAF plug and turn the ignition on
The 1 (W) should be the battery voltage

If they dont read the battery voltage of the approx 5v at those respective termianls there is most likely a short in the system so check the connectors harnesses and plugs if they don't read the voltages at idle then there is most likely a fault with the MAF.

[robbo71]

Your not going to believe it.
No fault codes detected..Done.
Checked the MAF voltages cold..OK
Checked the MAF hot..OK
Removed and cleaned MAF..OK
No error's and no real repairs BUT idle back to normal..Strange but true.

Thanks all.

[kingy]

The joys of modern motor cars

[Bob]

Thanks for letting us know. Strange that is now OK but these things do happen

[Bigrig]

Good stuff mate - can literally sometimes just be a piece if dirt/dust on the sensor that causes it to okay up ... I've never done the voltage testing, but have pulled out the MAF if idling strange, given it a spray irrespective if it looks dirty or not, and hey presto ... all good again!!

Glad it's sorted chief!!

[Bushy-Au]

Be careful!!!

I had loss of power at 3000rpm and thought I would check the MAF and clean it. I used a solvent spray then a cotton bud to wipe the surfaces, bad move.
I was told later to only use a MAF specific cleaning spray and not to touch any of the surfaces. After replacing the MAF I still have the loss of power problem which I can't seam to resolve.

I hope this helps.

[alexx]

Thank you for your info folks.