1103: DMC FW: ABS Error warning

[Peter.h]

I started getting this warning (1103: ABS Error) over the weekend, along with a red FAULT indicator and a flashing BRAKE indicator.

Would welcome any suggestions how to troubleshoot. I've done a fair bit of brake work on my older cars (fabricated lines, rebuilt a booster, installed pad wear sensors, etc.), but have no experience with ABS :-(

Where do I start troubleshooting? TYIA!

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Longer context / chain of events:

I started replacing the radio head unit over the weekend (will write up my experiences when it's done). Things went smoothly thanks to all the guidance on here (and $35 spent on Tesla service access for circuit and connector diagrams).

However, at some point I started getting Warning 525: ABS short circuit

I checked out all the wires in the areas I had touched (the circuit diagrams on the Tesla service page help identify them) and did not notice any obvious issues.

After a bit of googling I figured I should check the wheel speed sensors for voltage and resistance. I pulled the front left sensor wire, and found that I had 12V at the plug, but that the sensor itself had near infinite resistance (~3 M Ohm).

This error started occurring shortly after I plugged it back in. I removed, cleaned, and replugged several times, to no avail.

Separately I kept thinking about what may have gotten disturbed while I replaced the radio and got concerned about the thick wire loom at the switchpack (I could trigger an SRS warning by wiggling on the wires). On a hunch I unplugged, blew out, and replugged the 5 connectors on the switchpack (after inhibiting the APS) - and warning 525 (short circuit) and the SRS warning disappeared.

However, the 1103 ABS Error stayed :-(

 

[gregd]

Fuse?

 

[Peter.h]

Fuse?

Afraid not. Pulling the ABS fuse produces a different warning (1098: DMC FW: Lost ABS Comms (and TC) warning). Replacing the fuse brings the original error 1103 back

 

[Peter.h]

Any ideas, please? How do I start narrowing down this error?

 

[ML Auto]

I will assume you have checked the fuild level.

You need to get OPCOM software (for the vauxhall VX220) to access the trouble codes. Without it all you can do is check the speed sensors and inspect the connectors.

The sensors should have some resistance, you should test another one as well.

 

[Peter.h]

Thank you @MLAUTO

for the Opcom tool, how do you connect to the roadster? The DIAG port (where the OVMS sits) seems different from a regular OBD2 port - do I need to make a cable?

or can I use something like this?

MASO OP-COM V1.95 Opel OBDII Diagnostic Scanner Tool Interface Code Reader Compatible with Opel Vectra-C, Astra-H, Zafira-B CAN-BUS，TECH2 https://www.amazon.com/dp/B07HR9VVBY/ref=cm_sw_r_cp_api_i_pFpiFbN9J9FX6

 

[Peter.h]

To close the loop here:

I checked fluid (normal) and all the connectors (unplugged, cleaned, replugged). The error kept showing up every time the car turned on (open the door, turn the key, etc)

Then I went for a short test drive, and within 30 seconds the red FAULT light in the dash went off and the error hasn’t come back.

Would love to understand better what’s going on here: Does the car need to move to read the sensors after they are unplugged? Or is this sort of like a check engine code on an ICE car, where it stays until it is cleared (but somehow clears itself eventually)?

in any case, all seems well now

—-

Edit: I ordered the Op-Com software and cable and should get it next week. I’ll hook it up anyway to see what I can learn

 

[jfischer]

Thank you @MLAUTO

for the Opcom tool, how do you connect to the roadster? The DIAG port (where the OVMS sits) seems different from a regular OBD2 port - do I need to make a cable?

or can I use something like this?

MASO OP-COM V1.95 Opel OBDII Diagnostic Scanner Tool Interface Code Reader Compatible with Opel Vectra-C, Astra-H, Zafira-B CAN-BUS，TECH2 https://www.amazon.com/dp/B07HR9VVBY/ref=cm_sw_r_cp_api_i_pFpiFbN9J9FX6

@mlauto
I’ve got this tool but can’t figure out what to select for ABS.. speedster. Speedster/220 works for airbag but the ABS 430 selection doesn’t seem to connect to the ECU…. Any suggestions on what to select to get/clear ABS codes?