Famous p0172

Turn your meter dial ONE notch COUNTER-CLOCKWISE to DCV

 

Here

 

Ok got the reading at 4.99 volts. So it got power. But the secondary air pump did not turned on at cold start

 

I don't do this stuff everyday.
@Dm93 does.

But if you were to go off the flow chart.
All you can do is tests the Pressure Sensor at this point.
And I doubt your scanner has the ability.

These ECM don't fail often. Like almost NEVER.
If I were in your shoes, I'd feel safe throwing a pressure sensor at it.

BUT.......You should NOT do that.
What you should do is wait for Dm93 and maybe a couple other Techs to advise you better.

 

Ok so im getting this code only for now. Replaced the MAP with one i have on other truck and still the secondary air injection pump dosnt turn on.

 

everything seems clean.

 

Will your scanner show the Pressure Sensor value (AIR PMP PRS)?

 

Dont think so. This is what im getting now. I get the same error with the o2 sensor connected or disconnected. Been checking the wiring but dont see anything wrong.

 

I dont understand according to this im getting the heater circuit low error. But i do get a reading on the catalytic converter temperature.

 

The catalyst teperature is a calculated value, there is no temperature sensor.

Have you checked for power at the O2 sensor heater wire yet?

 

I dont know how to i got the tester but dont know how to use it on the wirinc.

 

Should i test it on dcv.

 

Yes, DCV. Key on, one lead to a known good ground and the other to Pin 2 (Blue/White) at the O2 Sensor connector, you should see battery voltage.

 

Ok if i do get the battery voltage on that test. Whats the next step. If i dont get battery voltage what to do too.

 

If we have battery voltage there then we'll need to go to the PCM and check there, if not then we'll need to find the broken wire.

 

Ok thank you very much ill continue tomorrow. Heatwave its hitting hard in sfl got a really bad headache.

 

Ok i ground the black end to the chassis and the possitve to the white and blue cable and showed me 10.90volts. And battery its showing me 12.38

 

That's a problem, do you have a test light so we can load the circuit?

 

The one with the clamp and one poont to the connector?

 

This one would work?