Your dash lights are likely one of those unrelated "It does this too." things. It's probably worth looking at and cleaning the ABS & 4wd controller grounds.
You'll need more than a multimeter or test light to check the signals from the PCM to the coils. They're self contained ignition systems with control signals off the PCM.
Anything made much after 1998 needs a scope to test some systems.
A Picoscope is nice but you need a reasonable Windows based laptop and the scope itself is pricey.
Single channel handheld Oscilloscopes are not that expensive anymore. Hantek sells some in the $60-$150 price range.
Here's a review of the Hantek handheld scope. Adrian Black has reviewed several inexpensive handheld and laptop connected scopes. You can find more reviews if you look at his channel.
This is his review of a Hantek handheld scope-meter.
Owon is compettitor to Hantek. This is Kerry Wong comparing an Owon to a Hantek handheld scope.
I have a Quad DSO and DSO Nano I purchased back in 2014ish. They're useful but I wouldn't recommend em for anything more than looking at waveforms. Add to that the non standard MMCX connector that limits your selection of probes. Measurement of frequency and voltage leaves more than a little to be desired as well.