Fans and knock sensor issues - aw11 4agze

[Jrad]

Car - 1989 AW11 Supercharged 4agze - running SC14 supercharger.

motor / part in question - ECU code 52 (knock sensor) and cooling fans

problem -

Hi guys, two issues that I believe aren't related.

Issue #1
Engine light comes on when driving. I have run diagnostics and it's telling me ECU code 52, knock sensor.
I've done a little research and apparently it's common on 4agze, especially ones that are running more than factory boost.
Is it something I should be concerned about? The engine seems to be running fine.
Is there an easy way to rectify it/stop it from throwing the code, other than pull the dash light out?

Issue #2
I believe that the radiator and side vent fans aren't kicking in when up to temp, and I don't have a working temp gauge on the dash.

I have done some troubleshooting:
If I disconnect the fans, they go into failsafe mode and run constantly - so they work.
I have tested the back of the dash with an ohm meter, and it's reading correctly.
I have checked the fuse for the dash (also runs oil pressure and fuel) and it's fine.
When switching the air-con on, the front fans kick in, then shut off and the light flashes on the A/C switch in the cockpit. It has been gassed and checked for leaks.

At this stage, I believe it may be a temperature sensor/sender. However there are 2 or 3 on the engine. The one at the back of the head is a single wire plug?
Would this sensor also cause the engine to idle a little high (1,500rpm) and run rich? If it's telling the ECU that the car is cold?
According to the BGB, there is also one at the front of the head - although it's hard to find in an AW11 engine bay.


Where do I go from here to rectify either, or both, issues?

Thank you in advance,
Jarrad.

[Matt]

For the temp gauge on the cluster.

Put a pin in the plug that connects the sender and earth it out on the block. If the gauge moves all the way to full then you know the cluster gauge is working properly. If it doesn't move, than the gauage itself or the wiring is faulty.

I've found when the knock sensor code is thrown, it usually is a faulty knock sensor.

[Jrad]

Thanks Matt,
LOL at the knock sensor comment - fair enough.
From research it's a pretty common issue on the 4agze



Are you saying plug into the wire in this diagram and earth it to the block?
(as this is the one removed to engage compartment the fan when the ignition is in "ON" position)

[Jrad]

Reporting back.

After digging in the horror of an AW11 engine "bay" (more like.. box/hole)
I found hidden under many kilometers of sludge, an unplugged wire (or few)

For those wondering - the sender at the front of the head is for the gauge. The rear is for the ECU

One of which was for the gauge on the dash. So that's fixed.