ECM Test Bench

[ryan.hess]

Hi guys...

Just an FYI, I am working on an ECM test bench. What does it do? Well, it allows you to simulate all inputs to most ECM's. You can test ECM's, trace down problems, test your own code, etc.

Features will include:

Lights for:
-Injectors
-Fuel Pump
-Fan 1
-SES
-Shift
-IAC
-TCC
-EGR
-Can Purge
-Air Select
+4 extra to play with

Digital Inputs:
-Ign PWR
-Switch for A/C clutch on
-Park/N switch
-Power steer switch
-Diagnostic switch with 3 position select resistances. (for ALDL)
-4? extra switches for whatever

Analog/Controlled Inputs:
-RPM
-VSS
-TPS
-MAP
-CTS
-IAT
-KNOCK
-o2 simulator
-FP voltage Input (adjustable 6-12V)
-3 additional pots for extra inputs

-Onboard RS232 coms

Most current estimated cost for parts and board will be around $100. Will vary depending on how many boards I order, and if I get a group buy for parts. I just need a headcount for people who would be interested. This WILL be put together whether anybody here is interested or not. Please only speak up if you are 90% sure you would purchase one if available in the next month or two. (There is no commitment, but I don't want to be stuck with 50 extra boards )Thanks,

[Fierobsessed]

So, your going to make a test box... Check mine out

I made a lengthy post about my testbox at Quad 4 forums... figured I'd share it here.

I invented a diagnostic device, it's probably the only one in existance like it. I have seen simular devices, but I believe mine is the only one that is an inline unit meant to work with or without an engine, or harness for that matter. best of all it can help do diagnostics on harnesses too. Basically it consists of indicator lights, potentiometers, switches, test points and an A/F guage.
The 5 potentiometers control:
MAP (green)
TPS (blue)
AC PRESSURE (grey)
CTS (yellow)
MAT/IAT (brown)
Colors were assigned based on the color of the input wire, that way I can remember

There is a 3 position switch above each potentiometer, and a testpoint above the switch, and one below the potentiometer. The testpoint above the switch goes directly to the input from the wire harness that can be plugged into the bottom of the unit. Putting the switch in the up position sends the signal from the harness to the computer, just like normal operation. Putting the switch in the middle position kills the connection to the computer. Putting the switch in the down position hooks the computer up to the potentiometer, witch is also hooked to the testpoint below it. This way you can probe your harnesses input, adjust the potentiometer to match that value, and then switch from your harnesses input to the potentiometer hopefully without the computer recognizing the difference, or the switchover. Pretty neat eh?

The lights are all digital outputs (Injectors, Fuel pump, Coolant Fan, Canister Purge, AC compressor control, Shiftlight/TCC Solenoid, and Check Engine light) I still need to add the switches for the digital inputs. (AC request, Power steering pressure, 2nd gear sw, 3rd gear sw, P/N sw, and Brake sw ect...) But the wiring inside is getting pretty wild as you can imagine.

I use an external power supply to turn on the unit, but plugging it into a harness will provide it with it's power as well. Infact you can turn the car on without the key by turning on the power switches. (one for memory power, the other for IGN) Of course the car will not start without the key still.

The ECM mounts to the back of the unit and the unit has the pigtails from a harness that plug into the ECM. The wires run straight through (with a stop at some switches and potentiometers, lights ect...) to a set of sockets that plug into the cars wiring harness in place of the ECM.

Iv'e even gone as far as to create accessories for this unit, although they are far from complete. A speedometer, a tachometer and an ALDL connector.
The ALDL connector might become a permanent part of the unit since I use that part the most. I'm finding this unit to be absolutly indespensable for helping me hack out the ram section of the program, witch is the key to understanding all the tables and charts. Overall this unit cost me a couple hundred dollars to build and several hours in my favorite electronics store, then I had to build it. I guess I get to name it too. I'll call it the HAXBOX.

I have registered my copy of EFILIVEv4 and have utilized the heck out of it. It helped me send all the ram addresses to the ALDL and analize the contents with the ECM running.

Since that post I have added the digital switches and indicators. The wiring inside is unbelievable. The unit seems to work quite well in the car, switchovers are seamless to the potentiometers. I'm finding that Temperature inputs on the ECM, while not designed for 0-5V input, accept that input every bit as well as a 0-5V input does. If I were to do this one over, I would not have based its design on the cars inputs, but rather all the inputs and outputs the ECM has, In other words, 8-9 potenitometers. and a few more digital inputs, and lights for ALL QDM outputs. I would also have liked to make it smarter, having a DIS simulator (reference pulse generator) a VSS generator, and an IACV position indicator, though my ALDL does that for me. One of the cool things Is I have two lights hooked up to the injector outputs, Iv'e had those lights lit solid bright, they barely light up at an Idle

This unit has been Absolutly indespensable in respects to testing code modifications, testing inputs, and especially modifying data streams; All in my living room.

[ryan.hess]

Messy. :P

I've had a rudimentary one hooked up... basically I just put a signal into the RPM input, and do whatever I need to do. Mine will look similar to this:



but it will have more features. (listed above)

[Fierobsessed]

Tell ya what, if you have the resources to make one as nice as that one, and it will run the whole gamut... Im in on it. Im one of the few that can appreciate a good test box. Especially after usiung my... well... discrete component compilation. I will make a list of features that I would like to see, we can compare notes. Im sure you are in it for the same thing.

[ryan.hess]

Sure, still looking for input. It's in the design phase right now.

[Fierobsessed]

Ok, so heres a list of every input/output the ECM has (or could have depending on model) Some are only listed as pin numbers.

Analog Inputs,
I listed the Temp thermistor inputs as 0-5V because they will accept it, though its not intended for this input normally.

Battery Voltage (not needed for test box, 0-25.5V Compatable)
F15 MAP (0-5V Compatible)
F14 MAP2 (0-5V Compatible)
E14 O2 (0Mv-1200Mv Compatable)
E16 CTS (0-5V Compatible)
F13 TPS (0-5V Compatible)
A3 TPS2 (0-5V Compatible)
E13 Pump Volt (0-25.5V Compatible)
F16 MAT (0-5V Compatible)
B3 MAT2 (0-5V Compatible)
E10 MAT3 (0-5V Compatible)
E11 (0-5V Compatible)
F11 (0-5V Compatible)
F12 (0-5V Compatible)
MAF F10 (Frequency? Or Voltage?)

Digital Inputs
Some are sinking, some are sourcing, each needs verification.

C4 Fan Request
C9 Ac Request
D10 Brake input
A7
C3
D2
D3
D4
D11
D12
D13
D14
D15
D16

Digital Outputs:
E7 SES
E8 FAN
E9
F1
F2
F3
F4
F5
F6
F7
F8
A11 Pump
A2
INJ A
INJ B

Misc, requires special circuitry

Knock Sensor
VSS
Ignition Signal
(MAF?)
(EGR?)

I can see how this test box would be rather large in size, I mean 14 Potentiometers and switches, 14 Digital inputs (1 swich and 1 light each) and 15 Digital outs (1 light each) Thats a shit load of components, But it would cover every obd1 ECM

I am still a huge fan of the Inline test box, meaning that a harness with sensors can be plugged into the box, and either directly interface with the ECM, so the test box can monitor, OR, control the ECM. But then again, there are two types of ECM connectors commonly used, the underhood quad plug ECM, or the standard tri plug ECM found in most cars, so either it can be compatible with both types, or just go with the tri plug since its most common. The sockets can easily be directly soldered to the testbox's PCB, and the plugs can be put on long Pigtails for more flexability.

Its nice to know that the ECM has a huge amount of expansion capacity, and they are only 20$ at the local U-Pull it.

[ryan.hess]

Ok, so heres a list of every input/output the ECM has (or could have depending on model) Some are only listed as pin numbers.

Analog Inputs,
I listed the Temp thermistor inputs as 0-5V because they will accept it, though its not intended for this input normally.

Battery Voltage (not needed for test box, 0-25.5V Compatable)
F15 MAP (0-5V Compatible)
F14 MAP2 (0-5V Compatible)
E14 O2 (0Mv-1200Mv Compatable)
E16 CTS (0-5V Compatible)
F13 TPS (0-5V Compatible)
A3 TPS2 (0-5V Compatible)
E13 Pump Volt (0-25.5V Compatible)
F16 MAT (0-5V Compatible)
B3 MAT2 (0-5V Compatible)
E10 MAT3 (0-5V Compatible)
E11 (0-5V Compatible)
F11 (0-5V Compatible)
F12 (0-5V Compatible)
MAF F10 (Frequency? Or Voltage?)

Digital Inputs
Some are sinking, some are sourcing, each needs verification.

C4 Fan Request
C9 Ac Request
D10 Brake input
A7
C3
D2
D3
D4
D11
D12
D13
D14
D15
D16

Digital Outputs:
E7 SES
E8 FAN
E9
F1
F2
F3
F4
F5
F6
F7
F8
A11 Pump
A2
INJ A
INJ B

Misc, requires special circuitry

Knock Sensor
VSS
Ignition Signal
(MAF?)
(EGR?)

I can see how this test box would be rather large in size, I mean 14 Potentiometers and switches, 14 Digital inputs (1 swich and 1 light each) and 15 Digital outs (1 light each) Thats a shit load of components, But it would cover every obd1 ECM

I am still a huge fan of the Inline test box, meaning that a harness with sensors can be plugged into the box, and either directly interface with the ECM, so the test box can monitor, OR, control the ECM. But then again, there are two types of ECM connectors commonly used, the underhood quad plug ECM, or the standard tri plug ECM found in most cars, so either it can be compatible with both types, or just go with the tri plug since its most common. The sockets can easily be directly soldered to the testbox's PCB, and the plugs can be put on long Pigtails for more flexability.

Its nice to know that the ECM has a huge amount of expansion capacity, and they are only 20$ at the local U-Pull it.

Thanks for the input. IMHO, you don't need to test all of the inputs/outputs at once. One potentiometer can be used to test your wideband input function and your wastegate input (or whatever). That's why I'll have a few extra pots and digital inputs, but not one for all of them. That would double the cost, and I doubt anybody would be interested. Additionally, in most ECMs, INJ A and B are the same.

[jpgcasual]

Hi, I´m interested in an ECU tester, then I would like to know more about your ECM testers, please if you pretend to sell these items please send information to my email capacitacionautomotriz@yahoo.com.mx