Oil Pressure Sensor/Gauge Wiring

[camino70]

Alright, I give. I can't seem to trace the wire from the sending unit at all.

Any advice on tracing it? My gauge doesn't move, even when grounding the sending units wire and running the truck.

I've pulled the cluster and reseated it, didn't play do anything else with it.

I've swapped the oil pressure sending unit with a known good unit.

Is there a year range EWD I can get away with or does it specifically have to be a 2003, 2003 LX470?

TIA!

 

[camino70]

When I turn the key, all of the gauges stay low for a few moments, they kind of jiggle (including the oil pressure), then they all move appropriately (except oil pressure).

Any advice on what cluster I could swap into a 2003 LX without causing a problem? I have easy access to a 2004 LC and 1998 LX.

 

[PADDO]

There’s big differences between pre and post 2003 models regarding the combination meter and how it’s controlled via the multiplexed bus, so the ‘04 LC unit potentially might work. I’ll dig through my 03 LX manuals and see what I can locate for ya that’ll help fault finding.

 

[camino70]

Bump
Any advice on troubleshooting?
Thoughts on swapping the cluster?

 

[Spike555]

Bump
Any advice on troubleshooting?
Thoughts on swapping the cluster?

Before you swap instrument clusters you need proof of your mileage and you will need to take your truck to the dealer to have the new odometer flashed to your trucks mileage.
To prevent odometer rollback digital odometers have flash memory and if the instrument cluster miles and the ECU miles do not match the odometer usually flashes the truck miles until it is re-programmed.

 

[2001LC]

Your probably resticked to 03-05 possible 06-07 LX instrument panels. A parts search comparison may shed some light. I like www.partsouq.com for researching parts. Having VIN #'s is very helpful, there're more models than I'd ever imagine.

IIRC the wire from the oil sending unit is part of main engine wire harness. It passes through the firewall on passenger side connect to modulars behind glove box. You may want to check those connection behind the glove box.

 

[camino70]

Thanks guys, I was thinking the cluster was dumb and just displayed what the ecu told it.
I'll start looking for the wire behind the glove box.

 

[2001LC]

I find bad wires from rodent chewed often. If you can find the EWD and trace to wire block behind glove box, then you can test wire of oil sending unit. But with entire instrument panel flashing, I suspect sometime else may be going on. But really I've no idea.

Perhaps start another thread with heading that suggest instrument cluster issue rather than oil sensor. Seems most every issue someone has dealt with.

 

[camino70]

I had a hard time tracing wires so got the tone generator out to see if that helped me.

Tone generator

• camino70
• Aug 3, 2018

Oil pressure wire

• camino70
• Aug 3, 2018

Traced the tone through the harness to the cluster plug.


Am I thinking about this right? I confirmed continuity with the wire.

Continuity

• camino70
• Aug 3, 2018

Now that the cluster is out, can I test the oil pressure gauge alone? Replace the oil pressure gauge alone? Any advice on disassembly?

 

[camino70]

I removed the shield and manually moved the oil pressure gauge. Reinstalled sans shield and we have movement.


By the way, a 98 LX had the same plugs, but didn't do anything when plugged in to the 03 LX.

 

[camino70]

Well that was short lived. Oil pressure gauge stopped again. Did I read about a stepper motor replacement in here somewhere? Any other thoughts?

 

[Spike555]

 

[camino70]

As in glue the gauge needle to quarter way up? Lol

 

[Mauser]

Before you swap instrument clusters you need proof of your mileage and you will need to take your truck to the dealer to have the new odometer flashed to your trucks mileage.
To prevent odometer rollback digital odometers have flash memory and if the instrument cluster miles and the ECU miles do not match the odometer usually flashes the truck miles until it is re-programmed.

You can also swap the eeproms between the two clusters. Or if you are good at figuring out hex code you can reprogram them.