Hi, after quite a bit of research and diagnostic on my car's no-start, I found a way to get engine codes from my van. It's the same as any other OBD1 Honda (even USDM) but I thought I'd save people some time by noting some specifics of our van/truck. I'm not 100% sure about how this works/if it does work on other vans/trucks, my van is an HH4 . HOW TO READ CODES You will need to find your 'diagnostic port' the OBD1 port is a small, blue, two-wire connector (that isn't connected to anything). Mine was near the fuse box under the driver's side dash area. Here's a picture (it's the one in the middle, not the three-wire blue, nor the two-wire green): Once you've found it, you need to jump the two pins. It needs to be jumped AFTER the ignition is turned on, with the ENGINE OFF (key position 2). I did this by unfolding a paper clip and jamming each end in the connector pins. If you've done this right, the engine light will start flashing, which will indicate the 'code' that the ecu has stored. You need to count the number of times it flashes. If it has multiple codes, it will do a set of flashes, take a quick break, and flash again. For example, my car had codes 3, 6, and 7; so it flashed 3 times, short pause, 6 times, short pause, and 7 times. After it has flashed all of the codes it will restart so keep noting down numbers until you get to one you've already seen. Here is a list of 'codes' and what they mean Codes 0 and 11 Electronic control module (ECM) Code 1 Heated oxygen sensor A Code 2 Oxygen content B Codes 3 and 5 Manifold absolute pressure Code 4 Crank position sensor Code 6 Engine coolant temperature Code 7 Throttle position sensor Code 8 Top dead center sensor Code 9 No.1 cylinder position sensor Code 10 Intake air temperature sensor Code 12 Exhaust recirculation system Code 13 Barometric pressure sensor Code 14 Idle air control valve or bad ECM Code 15 Ignition output signal Code 16 Fuel Injector Code 17 Vehicle speed sensor Code 19 A/T lock-up control solenoid Code 20 Electric load detector Code 21 V-TEC control solenoid Code 22 V-TEC pressure solenoid Code 23 Knock sensor Code 30 A/T FI signal A Code 30 A/T FI signal B Code 41 Heated oxygen sensor heater Code 43 Fuel supply system Code 45 Fuel supply metering Code 48 Heated oxygen sensor Code 61 Front heated oxygen sensor Code 63 Rear heated oxygen sensor Code 65 Rear heated oxygen sensor heater Code 67 Catalytic converter system Code 70 Automatic transaxle Code 71 Misfire detected cylinder 1 Code 72 Misfire detected cylinder 2 Code 73 Misfire detected cylinder 3 Code 74 Misfire detected cylinder 4 Code 75 Misfire detected cylinder 5 Code 76 Misfire detected cylinder 6 Code 80 Exhaust recirculation system Code 86 Coolant temperature Code 92 Evaporative emission control system (from https://axleaddict.com/auto-repair/Honda-and-Acura-OBD1-Trouble-codes-How-to-read-and-what-they-mean) And that's it. Hopefully this helps with your diagnosis. If I couldn't get the information across to you, here is a good video by ericthecarguy on youtube, just note that he is doing it on a different car so there are some differences EDIT: made the picture smaller
