I bought an audi A3 -96 recently that had the ABS warning light on. I thought that it was probably an easy fault, maybe a broken sensor or something. However, now I have investigated a little bit more and it seems like I have a problem with the ABS pump unit.
I connected wbh-diag tool with my USB-ODBII cable and pulled the code for the ABS controller. Code was "01276 - 16". Searching Ross-tech gave the following description:
01276 - ABS Hydraulic Pump (V64): Signal outside specifications
One common fault for this code on several VWs seems to be bad connection to the fuses above the battery or the ground ground point to chassis. I have checked this and measured all the pins in the connector to the ABS control unit.
Supply has stable 12,7V on both lines. Also supply from 5Amp fuse from fuse box inside car shows correct voltage when key is in right position. All wheel sensors show about 1kOhm when measuring from the pins in the connector. The hydraulic pump itself shows 1,2Ohm. It not not possible to delete
the error code.
1. Is 1,2 ohm a normal value for the hydraulic pump motor? I have searched the net now for days without finding anything. Could someone help me by measuring their pump? It only takes about 10 minutes to do it.
2. It does not seem that wbh-diag can do the same test as Vag-com. Is there any other free tool that can test the hydraulic pump?
3. Has anyone taken one of these pumps away from valve block? Is it possible to do so without having oil leakage? Would it be possible to change the motor without having to bleed the brakes?
4. Does anyone have a picture how the pump/motor looks like when it is taken away from the valve block? What does the connection look like? Maybe someone has a old broken one which can be dismantled and photographed?
5. Would it be possible to bleed the brakes without VAG-com?
6. Does anyone know how the ABS control unit tests the pump? Is it only a resistance measurement, or something else?
7. Any other tips?