Innova scanner not working 88 5.0

Idkwhatimdoing · Jul 9, 2026

I bought a scanner to diagnose my high and surging idle but when I plug my scanner in and press test when I have the key turned to on nothing happens but apparently the CEL is supposed to come on briefly when I turn on my car which it doesn’t along with all of the warning things as well do not come on any insight would be great

Mustang5L5 · Jul 10, 2026

Idkwhatimdoing said:
I bought a scanner to diagnose my high and surging idle but when I plug my scanner in and press test when I have the key turned to on nothing happens but apparently the CEL is supposed to come on briefly when I turn on my car which it doesn’t along with all of the warning things as well do not come on any insight would be great

1988 Speed Density cars do not have a CEL. You can certainly add one if you want, but it will not prevent you from using the Innova. 1988 Cali MA air cars do have the CEL

Electrical Thread 'Foxbody Mustang: Adding Check engine light to 86-88 cars'

Nov 22, 2021

As some may know, the early Speed Density 86-88 5.0 cars did not come with a functional Check engine light. The 86 cars never had the means to display a CEL. The 87-88 cars do have a spot for the CEL under the tach, and part of the dash wiring. This, however, was solely for the 2.3L Mustangs

The pin on the ECU that matters here is Pin 17. On the '89 and later cars with a functioning CEL, Pin 17 would have a wire going to the EEC4 test connector and a wire going to the gauge cluster light. Pin 17 is a ground that the ECU can switch. By closing the circuit to the dash bulb, the...

I assume you have the Innova 3145? If so, follow these directions. Make sure you have a battery in the tester, as it's commonly assumed it is powered by the vehicle. You do need a 9V in there

View: https://youtu.be/Hwtm6avQMPc?si=j5UKD-Rp5KxfOEG5

General karthief · Jul 13, 2026

Idkwhatimdoing said:
along with all of the warning things as well do not come on any insight would be great

do all the gauges work?
did you just get this car or what's the story?

Innova scanner not working 88 5.0

Idkwhatimdoing

New Member

Mustang5L5

That is…until I whipped out my Bissell

Electrical Thread 'Foxbody Mustang: Adding Check engine light to 86-88 cars'

General karthief

wonder how much it would cost to ship you a pair

Similar threads

Innova scanner not working 88 5.0

Idkwhatimdoing

New Member

Mustang5L5

That is…until I whipped out my Bissell

Electrical Thread 'Foxbody Mustang: Adding Check engine light to 86-88 cars'

General karthief

wonder how much it would cost to ship you a pair

Similar threads

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