What items to check before replacing ECM on '90 APV?

Hi, I didn't have much luck Googling this one, so thought I'd ask the group...
On Monday my ECM failed suddenly while driving. (The comedy of errors I went
through before arriving at the correct diagnosis is its own story.) The remanufactured ECM worked perfectly on several short trips, but failed the day after installation. This time it did not fail while driving, but the vehicle wouldn't start, with the same symptoms. (Cranks fine, no gas, no sound of fuel pump when ignition is turned on, fuel pump runs from test point.)
Other than the fuel pump relay, what other items should I be checking for low resistance? (Which I gather is the most common demise for these units) Perhaps I just got a bad ECM, but I want to make sure I don't have some other problem. Anything else I should look for?
Thanks much, Bruce Adams
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You want to check the resistance of all of the output driven devices, this includes the injectors, the EGR solenoid, the purse solenoid (if it has one), the torque convertor clutch solenoid (beware of the third gear switch that doesn't close until the transaxle shifts into 3rd gear), the idle air control valve (2 windings), the cooling fan relay and the AC compressor relay. Check all power circuits, orange are constant battery power circuits, pink/black are ignition on power circuits. Check all grounds also. An easy voltage drop test for the ECM ground circuits is to; jumper the ALDL, turn the ignition on, connect one lead from your VOM to the ALDL jumper, connect the other lead from your VOM to battery negative, hopefully you'll see less than .1 volt. (this procedure correctly loads the circuitry allowing an accurate determination of voltage drops on the ground side of all ECM circuits.)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.