P0418 help

Hello all,
First time poster, long time reader. Here’s my issue:
P0148 code secondary air pump not working.
Here’s what I’ve done:
Applied 12V to pump. Pump works. 50 amp fuse has continuity. Swapped the AI valve relay with horn relay. Relay works. Checked voltage at connector to pump. Voltage moves wildly between 49 and 0 volts.
I would love some help on this good people.

 

Did you remove the pump lid to make sure the filter inside is in one piece and not broken and clogging it? Some people remove the internal filter and install this, instead

 

Yes. Replace filter with unifilter. No damage or deterioration on stock foam filter. Thank you

 

One more thing I should have included. My 50 amp “Air Pump” fuse was missing which is strange because I have never touched that fuse and no one has worked on this truck but me. And, the code is recent. I replaced the fuse with the 50A spare.

 

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Have you checked powers and grounds at the Air Injection Control Driver Module and inspected the wiring between the module and the pump?
Toyota's flow charts suck but I attached the one for that code, best I can tell it can be a wiring issue, a faulty pump, or a faulty driver module.

 

Thanks so much. Do you know of any videos or info for testing the driver module? I know the pump is good as I have tested it.

 

I can't say that I've ever tested one or even heard of one failing, are you sure the pump isn't drawing too much current even though it runs?
Also have you cleared the codes since you reinstalled the fuse?

 

Problem solved. The 50A fuse was missing. I don’t know how that happened as I never too it out. Only work done on my truck by mechanics was new tires. It remains a mystery. Thanks for all the great advice. Love the uni-filter.