Reading AHC Pressures w/ Carsoft (1 Viewer)

[silver02accord]

I ordered this Carsoft tool to measure AHC pressures. I measured the truck in L, N and H.

For L mode(and N and H) on each of "Front Pressure Sensor","Rear Pressure Sensor" and "Accumulator Pressure Sensor" the measurement is 0 Mpa-g.

I meausred these values while the car was off. Am I supposed to move the car from low to neutral or netural to high? These numbers of 0 don't seem valid.

Secondarily I had a CEL light on and it through p0441(evaporation emissions control system incorrect purge flow) and p0455(evaporative emission control system leak detected(gross leak). These codes were in the history as well(car passed smog before the CEL light came on). I replaced the gas cap today but per the lexus dealership diagnosis(which seller gave) the leak detection pump, vsv and related hoses needed to be replaced. Is there any harm driving on this besides lower mpg?

 

[ramangain]

AHC is an active test to read the pressures. Watch the values WHILE the vehicle goes from L to N. The final readings are the ones people reference in this forum.

 

[silver02accord]

AHC is an active test to read the pressures. Watch the values WHILE the vehicle goes from L to N. The final readings are the ones people reference in this forum.

thank you. should i also check N to H?

 

[ramangain]

You can; it won't hurt anything. When comparing values you see in the forum however, the benchmark is the readings when the L to N test is complete.

 

[silver02accord]

You can; it won't hurt anything. When comparing values you see in the forum however, the benchmark is the readings when the L to N test is complete.

Ok just ran it, I did it 3 times.

Front Pressure Sensor ranged from 6.9-8. Rested at 7.9 once and 8 twice.

Rear pressure seemed a narrower range, read 6.8, 6.9 and 7.10

Rear accumulator at 10.30.

Update:

Also would like to add the heights from the L to N Test: FR, FL and RR. They are reading FR -47.60, FL -51.60 and RR -22.20. I see lots of people posting 0 for these numbers?

 

[suprarx7nut]

Ok just ran it, I did it 3 times.

Front Pressure Sensor ranged from 6.9-8. Rested at 7.9 once and 8 twice.

Rear pressure seemed a narrower range, read 6.8, 6.9 and 7.10

Rear accumulator at 10.30.

Update:

Also would like to add the heights from the L to N Test: FR, FL and RR. They are reading FR -47.60, FL -51.60 and RR -22.20. I see lots of people posting 0 for these numbers?

Those pressures look a little high. Time to crank those torsion bars and re-test. The full procedure should be a little more involved than that, but the quick and dirty is just to tighten those torsion bars 1 turn on each side and measure again.

The heights should be very close to 0.0 when in N. The system targets 0, but it's typical to have some variance. -47.6, -51.6 and -22.2 sound like L mode heights. Are you sure you waited until a minute after it settled on N? The diagnostic system has some latency so you have to wait a while.

 

[silver02accord]

Those pressures look a little high. Time to crank those torsion bars and re-test. The full procedure should be a little more involved than that, but the quick and dirty is just to tighten those torsion bars 1 turn on each side and measure again.

The heights should be very close to 0.0 when in N. The system targets 0, but it's typical to have some variance. -47.6, -51.6 and -22.2 sound like L mode heights. Are you sure you waited until a minute after it settled on N? The diagnostic system has some latency so you have to wait a while.

I think those were the L heights you are correct. I ran some new tests and got 1, -7 and 5(rear). I did not wait very long before taking my eye off the meter or retesting so it may not have settled fully, as another time I got 1.4,-6.8 and 4.4. I'll give it some more time and try that one again.

I don't think the springs have been replaced so I will try the TB and see if I can get both in spec-if not I'll look for new springs(and 30mm spacers it seems?)

 

[silver02accord]

Those pressures look a little high. Time to crank those torsion bars and re-test. The full procedure should be a little more involved than that, but the quick and dirty is just to tighten those torsion bars 1 turn on each side and measure again.

The heights should be very close to 0.0 when in N. The system targets 0, but it's typical to have some variance. -47.6, -51.6 and -22.2 sound like L mode heights. Are you sure you waited until a minute after it settled on N? The diagnostic system has some latency so you have to wait a while.

Also going to do a flush as soon as fluid arrives. I am getting 9 ticks on the reservoir.