I believe, when ECM is put into diagnostic mode, all output devices are turned ON.
This means, as look at the Haynes manual following along,
all devices the ECM controls (outputs), battery power is on one side of the device ECM is on the other terminal,
when device activated by ECM, the ECM line becomes low with respect to ECM ground, not chassis ground - device is ON. Device OFF, battery power on both terminals of device.

You should use a digital meter because of the high internal resistance within the meter not causing a large current demand on the ECM driver as the light bulb may break the driver stage, then ECM replacement is needed.

 

but my prom... do they go bad? do i need to worry about replacing the prom?
just take my old prom and put it into the new ECM right?

 

Correct, unplug ECM from car, remove cover on case, swap prom, reverse assembly.

 

So i have to buy a new prom and ecm separately, i cannot find them to come all together. zzz

 

So you're saying in order for me to check the EGR solenoid, i should use a digital meter? so touch the black end to the frame and the red end to each opening in the solenoid ? and measure Dc current for 12 amps? ><

 

Measure DC Voltage
ECM ground/reference is usually 0.4-0.6 volts
battery voltage will be on the other terminal.

All ECM controlled devices have battery power on one of the terminals supplied by an ign controlled relay.
Look in the Haynes manual engine circuits.
If device has a good coil resistance - no opens
- then battery voltage will be measured on the other terminal WHEN ECM has not commanded the device on.

Haynes may state differently, but my GM/Helm service manual for my '88 Chevy Dually states when ECM in diagnostic mode, pins A & B of OBD connector are shorted together, output devices are turned on, i.e., injectors, purge solenoid, etc.

 

Ok well, i'm not the best with an ohm meter.

However, i did notice something today.

Today my car did something it has never done before,

I died on me about roughly 3 times today.. ALL WHILE MAKING RIGHT TURNS...
And the few times it has died before, was also during slowing down right turns.

it seems to me like the power steering takes a lot of power from the engine when i go to turn..

Given this information, any ideas as to what could be the issue?

 

Any load onto the engine, i.e., A/C, lights, PS, select a gear, etc.,
the ECM/PCM should open up the controlled vacuum leak - the IAC motor to increase idle speed as unloaded rpm whatever it may be designed.

Doesn't matter whether a left turn or right turn, unless a loose connection?

 

Whew, ok i finally gave up and took it into a shop Q_Q... It took them an hour tops to figure out the issue,
The issue was a broken wire that connects to the Map sensor.
They soldered a new connector and charged me 75$ out the door.

The car runs great now.
Idk what to do with the prom and ecm i just ordered though ... hmm