C1034 — 2 documented meanings by make

C1034 does not mean the same thing on every car — manufacturers reuse the number for different faults. 2 makes document it: Chrysler, Mercedes-Benz. Find your make below.

C1034 on Chrysler

On Chrysler vehicles C1034 is documented as: Rear right wheel speed sensor signal performance. C1034 points at ABS / wheel speed (rear right). The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Related Chrysler codes:

C1034 on Mercedes-Benz

On Mercedes-Benz vehicles C1034 is documented as: ESP no signal via CAN from the ETC (electronic transmission control unit). C1034 is stored when the ECU sees no signal on transmission. That describes how the circuit is behaving, not which part has failed — the wiring, the connector and the component itself can all produce it, which is why the checks below start with the cheapest.

Usually one of: Module has no power or no ground; Broken bus wire or a bad splice in the network; The module itself has failed; Terminating resistor or bus fault taking the network down.

Check first, cheapest first:

1. Check power and ground at the module before suspecting the module itself
2. Read whether other modules on the same bus also report faults — that separates a network fault from a single module
3. Inspect connectors at the module and any inline joints
4. Measure bus resistance across the two lines at the diagnostic socket
5. Replace the module last, once supply and network are proven good

Related Mercedes-Benz codes:

Which one is yours

A generic OBD reader gives you the number, not which of these meanings your manufacturer assigned to it. To get to the specific one:

1. Use a brand-specific scanner — VCDS for VAG, INPA or ISTA for BMW, XENTRY for Mercedes, Forscan for Ford. It shows the manufacturer's own text rather than the generic one.
2. Read all stored codes together — the neighbouring ones usually point at which system is involved and narrow the list.
3. Check freeze-frame data: the RPM, temperature and load at the moment it triggered indicate which system was active.
4. If you have no brand scanner, tell me the make and model below and I will tell you which of these applies to your car.

Code family

C1xxx is suspension, steering, active systems.

Severity

Suspension or steering — on active systems (ESP, air suspension) the code usually comes from a sensor, not the part itself.

That is what holds for C1034 in general. From here it depends on your engine — tell me which car it is and what it does, and I will give you the steps for it: real procedures, torque figures and diagrams instead of general advice.