75ZT Community

Bermudan 75 · Posted 05 May 2025, 18:10 #1

I have connected my car to the PSCAN reader and it is showing:

Wheel speed sensor front left open circuit.

I understand that this could be a break in the wire from the sensor to the ABS (Antilock Braking System) unit.

How do I find this break in the wire? Is there a usual location?
Can I use a multimeter to check if the sensor is working?
If so how?

The sensor is a genuine MGR part from DMGRS.
The front hub is new and has had a new bearing fitted.

Thanks

Mike

Arctic · Posted 06 May 2025, 08:20 #2

Hi Mike.
I would get in touch with DMGRS (Mat) and say the sensor is a dud and let them send you out another one and see if that's the same, if so then you know something else is wrong was the bearing put back in the right way round.

You can use a multi meter to test the sensor i did an how to somewhere on the other side may have done it on this side too?

If it is a line fault, ie the ABS ECU (Engine Control Unit) is seeing the FNS front left as open circuit

You need to make sure the plug on the car harness is not damaged, or the contacts pushed in

If an ABS sensor is open circuit, the ABS self test when the ignition is cycled results in the ABS MIL lamp staying lit, if it is a plausibility fault, it will extinguish, then come back on when driving

Bermudan 75 · Posted 06 May 2025, 09:14 #3

Thanks Steve,
The main ABS connector has never been disconnected so that should be OK. The bearing is definitely fitted the right way around.

I will swop the sensors around, the RHS is working OK, will keep you advised.

Mike

Duncan · Posted 06 May 2025, 14:58 #4

Worth checking the main connector as I have seen them with corrosion in. I don't believe the bearing would cause that fault code. The normal place for damage is the wiring on the sensor itself when it gets worn by the wheel if improperly clipped after work.

Bermudan 75 · Posted 07 May 2025, 09:53 #5

Last night the PSCAN was running rather slowly and I heard clicking from under the bonnet and the ABS light went out.

The car battery needed to be recharged so I closed PSCAN, switched the ignition off.
When I switched the ignition back on the rather dim lights showed the ABS light on and then off.

Recharged the battery overnight and the ABS light is back on.

I will check the main connector for signs of corrosion.

suzublu · Posted 07 May 2025, 16:59 #6

The wire on mine wore through by rubbing on the tyre.

Sent from my SM-A145R using Tapatalk

Duncan · Posted 07 May 2025, 18:49 #7

suzublu wrote:The wire on mine wore through by rubbing on the tyre.

Sent from my SM-A145R using Tapatalk

Yes, that's the most common failure.

Bermudan 75 · Posted 07 May 2025, 18:55 #8

I have checked the ABS module wiring socket and it is clean, dry and corrosion free.
PSCAN keeps saying nearside wheel sensor open circuit, so tomorrow I will order a new sensor and take it from there.

Duncan · Posted 07 May 2025, 19:07 #9

Swap the two front sensors, no need to put them in the hub. Does the fault code move?

Bermudan 75 · Posted 08 May 2025, 12:31 #10

Duncan wrote:Swap the two front sensors, no need to put them in the hub. Does the fault code move?

Yes both show as being open circuit, does that mean that the near side sensor is faulty?

Duncan · Posted 08 May 2025, 15:50 #11

Bermudan 75 wrote:
Duncan wrote:Swap the two front sensors, no need to put them in the hub. Does the fault code move?

Yes both show as being open circuit, does that mean that the near side sensor is faulty?

It does sound like it. Can you try to clear the codes? If you can clear one but not the other, then that kind of proves it I reckon.

Bermudan 75 · Posted 08 May 2025, 21:50 #12

Yes the code for the drivers side sensor clears.

Duncan · Posted 09 May 2025, 13:28 #13

Just so I'm clear. The fault started passenger side. You swapped the sensors over. You then had codes for both sides, but the drivers side could be cleared but the passenger not? That means the sensors are both OK, but the circuit on the passenger side is faulty. So plug, wiring, or ABS module. It isn't unknown for the wiring harness to rub throughinside the wing where it runs along the top of the chassis rail and then tucks under it right by the firewall.

Bermudan 75 · Posted Yesterday, 18:12 #14

Thanks Duncan,

I am beginning to wonder that the connector from the car harness to the sensor is the problem.

I tested it with a multimeter and it showed open circuit.

daveo138 · Posted Yesterday, 21:37 #15

Duncan wrote: That means the sensors are both OK, but the circuit on the passenger side is faulty.

Surely if the sensors are swapped over and the fault then shows on the driver's side, the sensor is faulty, no?

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ABS Warning Light by Bermudan 75