Latest Reader Question (April 1, 2018)

Here’s the latest reader question, along with my reply:

Elmer asks: I have a 1993 Ford Ranger XLT. I bought it new. This year at smog test time, it passed the smog test but it failed the safety test. The engine warning light, part of the instrument cluster, does not come on when you start. Therefore, I can’t register my pick up as a legal vehicle. I and my mechanic have been trying to find the cause for two months. As you know Haynes and Chilton service books leave much to be desired. In fact the electrical schematics are worthless. Now my question: Where can i go to get a PDF copy of 1993 Ford Ranger XLT 3.0L automatic transmission? I have tried the Internet and so far I have been unable to find what I need.  I hope you can point me into the right direction.

My reply: Well, I’m confused!

The emissions inspection includes checking that the “check engine” light in the dash illuminates at start-up and then goes out once the engine is running. This light is technically the Malfunction Indicator Light and if it comes on and stays on, it indicates a stored code/fault with the emissions system.

There is no “engine warning light,” per se. I therefore assume you are referring to the check engine (MIL) light – in which case you have an emissions issue – not a safety issue.

Now, there is another light – the SRS light. This one does pertain to the safety inspection.

“SRS” is the acronym for the Supplemental Restraint System, which in most cars means the air bag system. Part of the safety inspection is checking that the SRS light comes on at start-up and then goes out once the car is running. If it stays on, it indicates a problem with the SRS (air bag) system and the problem must be repaired before the car can legally pass the safety inspection.

So, we need to determine which light is coming on.

Now, digging deeper… .

I am pretty sure your 1993 Ranger does not have air bags. I think the first year for the air bags was 1995. However, you may have the (wait for it!) Supplemental Restraint automated seat belt system. In the argot of federal regulatory-speak, “SRS” included the automated shoulder belt system as well as air bags.

So, if the SRS light is on, it indicates a problem with the automated seat belts – which must (like air bags) be operating per factory design in order to pass the safety inspection.

If, on the other hand, it’s the MIL (“check engine”) light, then you have an emissions-related problem and now it’s a matter of determining how to find the trouble code in order to know what the problem is.  I am pretty sure your Ford has the earlier version of OnBoard Diagnostics. The current/recent version is called “OBD II” – and there is a universal plug-in port in all cars, regardless of type, that you plug a scan tool into to access/clear the codes and re-set the “check engine” light.

However, I think your ’93 has the earlier system, which does not use the universal OBD II plug-in port and scan tool.

I found something that may be helpful, though (see here and show this to your mechanic). He should have the necessary Ford scan equipment to access the Ranger’s computer to figure out what’s triggering the “check engine” light.

Hope this is helpful – and please keep us posted!

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