I have the apparently (after searching) infamous code 52 on my 88 4x4. I've read up on the issue on this and other forums, and as a result double and triple checked the wiring:

- there's continuity between the pigtail spade connector and the KNK pin on the ECU harness)
- there's an open circuit between the KNK pin on the ECU harness and ground
- There's an open circuit between the 'hot' lead on the pigtail and ground
- There's continuity between the shield on the wire, and ground.

Which leads me to believe either the knock sensor, or ECU, is bad.

Is there anything I'm missing that this could be? Hit the junkyard last weekend to try to find a replacement but both trucks were carbureted, so no sensors to be found to try. Local parts stores want $150+ so that's out.

Any/all advice appreciated. Would really like to get the power back in this truck.

 

175 bucks at toyotapartszone.com, OEM product.

You can find a $40 one, but.. I wouldn't.

 

The ECu is a rock solid piece of equipment and would be least likely to fail in my opinion. I have never had a bad Knock Sensor and most common is the wiring. I am not the best with electrical so am just going by experience.

 

Check that the shield is continuous, and that it is not grounded at the engine end. This is all visual; ground is ground to a multimeter. You're looking for some place that electrical noise can get past the shield.

I agree with Terrys87; the knock sensor itself is very tough, and ECUs just don't fail that often.