Just got the motor rebuild, single turbo, redid and connect all harness. Cluster work just fine before.

Turn Key to ignition:
1) Cluster light work for coolant, oil pressure, tach, and odometer reading, abs light, airbag, battery light. Dimmer & light switch work.
2) Car starts and hold idle if I crank it.

Why do I have no CEL on the cluster?
Check the bulb in the back, still good.
Check the diagnostic box, Ten + ground, no cel light at all.
Check ground harness connected to PFC, connected.

What am I missing?

 

PFC= no cel light

 

So pfc = no cel. But there should still be cel if you jump it through the diagnostic box?

 

bump old thread...

so does the pfc disable the cel all together or is it a option in the ecu where you can turn it on and off? i would like to have a cel on when there is a problem so i know...

 

The PFC can't do codes like the normal ECU does. You can look at the sensor check screen in the commander and see the status of all the sensors and switches, actually far more useful than a CEL.

Dale

 

hey dale,

how would that show me if there was a misfire or lean (false air) condition?

 

You need a wideband for that type of information (at least on the lean conditions). The stock ECU isn't going to tell you any of that either. The PFC commander has a diagnosis screen which will show you the voltage readings for all of it's known sensors. You will be able to tell if a sensor is not reading properly (similar to the CEL).

 

I still don't like the idea of not having a cel on. If the car is misfiring I want my cel to turn on.. plain and simple.

I understand how to use wideband, egt, etc gauges for diagnosis but if there is a problem and the pfc doesn't turn the cel on then I might need to start looking at different ecu. I would be fine with the pfc having a "force readiness" type of thing like obd2 systems but to not give you a heads up on anything, not even o2 sensors then that sucks. Also a sensor voltage reading won't show me a misfires.. or lean fault, it will only tell me of there is a voltage issue with that particular sensor.

Also since I never had a stock ecu, does that monitor the status for cel?

 

The stock ECU stores fault codes, yes. However, it doesn't do any of the monitoring you are wanting. Here are the codes which the stock ECU will store (and not all of the codes trigger the CEL):

Check Engine Light Codes

 

Thank you for that link! Now I understand why the sensor status is more helpful then a cel...

Also can't I just read codes with the odb1 scanner? Or is it only possibly to do it with the "flash" method?

 

the PFC doesn't even interface with the factory USDM check engine light, it interfaces with the exhaust overheat light on the USDM models since the PFC was designed solely for JDM cars. you can hack it to work for the check engine light but it will not display codes like the factory ECU does, it will only illuminate the lamp if the ECU has a malfunction.

so basically, with a PFC you will never get the CEL to illuminate unless you rewire it.

if you need it for emissions, tie the CEL to another lamp that illuminates on key cycle and turns off after testing is complete. normally i hate giving emissions bypass advice but in most cases you can make a PFC tuned car run better and burn cleaner than those with the stock ECU which may have underlying issues that are difficult to resolve without tuning ability.

 

Part of the problem is you're coming from a world of OBD2 cars that have WAY more powerful stock ECU's than the FD has. What you're wanting you won't get in an FD, unless you MAYBE go with one of the high end ECU's that are a BIG job to wire up and tune in.

The stock ECU doesn't have any sort of real-time monitoring or anything that you can do, and you can't use a scanner to get any realtime info from it. Again, you're talking a pre-OBD2 primitive ECU. You just get a CEL if a sensor is damaged or unplugged, that's about as good as it gets.

The PowerFC does have a lot more capability. I have a writeup on how to wire up the PFC to light the check engine light - with that done, the CEL will light up and go out when you start the car (which many states require for emissions testing). Also, the CEL will flash if you have knock that's too high or injector duty cycle that's too high, which is a good "hey dummy let off the gas" warning. Again, this is only if you do the rewire trick, but it's very simple to do. Stock it supposedly lights the Overheat Warning light, but that does NOT light up. Japanese cars are setup differently, the Overheat light is on the instrument cluster and is controlled by the ECU.

The PFC is hands down the most popular ECU choice on the FD. It's super easy to plug it in and run it, there's tons of support for it, it's very flexible, and it's priced reasonably. If you want something more, you're going to pay a LOT more, have a LOT more work to wire it all in, and a LOT more work to get the car running and tuned in. IMHO this option is more for the 1% of guys that are looking for the last bit of power, love to tinker, or have used the PFC and now want more.

Dale