Crank High Line

[aminga]

I've been going through the ECM Connector voltages to diagnose my no start and I found one anomaly.

The Crank Ref High on B5 says it "depends on the position of the vane in the sensor. if the vane is in the sensor it should be low. Now I've verified that the sensor is in a window on the reluctor ring and the voltage is still low.

The behavior of the sensor is exactly the opposite. The sensor signal line is high when the window is in the sensor and low when the vane passes

SO:

Is this correct that there should be voltage on the on B5 when the reluctor window is in the sensor

Could this cause a no start?

 

[TurboBob]

you will not be able to check this that way.


The crank sensor signal goes thru the ignition module, and the ignition module blocks it until it is sync'd

But from my testing, once the module starts letting the crank signal thru, it will continue to do so until you key off.

So, this testing could work if you crank it over first until you get at least one injector pulse. Then, leave the key on and do your checks.

Once sync'd, the ignition module passes the signal thru without modification, so high at the sensor = high at the ecm. Not sure about vane / no-vane, but the rising edge of the signal is at 10* BTDC.

Bob

Bob

 

[BlackBandit]

If the vane is in the sensor you should have 0 VDC on pin B5. If the window is in the sensor (or the sensor is unplugged) you should have 10 VDC on B5. Mine has 7 VDC and runs fine. It should work key on engine not running like this.

 

[aminga]

Once it synced it had voltage on B5.

All the ECm feeds looked normal after that.