U1131 — 7 documented meanings by make

U1131 does not mean the same thing on every car — manufacturers reuse the number for different faults. 10 makes document it: Audi, Chevrolet (USA), Chrysler, Ford, Jaguar, Mazda, Mitsubishi, SEAT, Skoda, Volkswagen. Find your make below.

U1131 on Audi, SEAT, Skoda

On Audi, SEAT, Skoda vehicles U1131 is documented as: Invalid or missing data for fuel system. U1131 is stored when the ECU sees range or performance on the circuit named in the code. 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: Sensor reading is inside its electrical range but does not match reality; Contamination or deposits changing what the sensor sees; A mechanical fault upstream that the sensor is correctly reporting; Sensor drifted with age without failing outright.

Check first, cheapest first:

1. Compare the live value against a second sensor or a known-good figure — this code is about plausibility, not a dead circuit
2. Look for the mechanical cause first: leaks, restrictions or wear that would genuinely produce this reading
3. Clean the sensor if it is the type that fouls
4. Check freeze-frame data to see under what conditions it triggered
5. Replace the sensor only after the mechanical side is ruled out

Related Audi, SEAT, Skoda codes:

U1131 on Chevrolet (USA)

On Chevrolet (USA) vehicles U1131 is documented as: Loss of serial communications for class 2 devices.

Related Chevrolet (USA) codes:

U1131 on Chrysler

On Chrysler vehicles U1131 is documented as: Lost communication with tyre pressure trigger module. U1131 is stored when the ECU sees no signal on CAN bus communication. 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 Chrysler codes:

U1131 on Ford

On Ford vehicles U1131 is documented as: SCP (J1850) invalid or missing data for fuel pump status. U1131 is stored when the ECU sees range or performance on fuel supply. 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: Sensor reading is inside its electrical range but does not match reality; Contamination or deposits changing what the sensor sees; A mechanical fault upstream that the sensor is correctly reporting; Sensor drifted with age without failing outright.

Check first, cheapest first:

1. Compare the live value against a second sensor or a known-good figure — this code is about plausibility, not a dead circuit
2. Look for the mechanical cause first: leaks, restrictions or wear that would genuinely produce this reading
3. Clean the sensor if it is the type that fouls
4. Check freeze-frame data to see under what conditions it triggered
5. Replace the sensor only after the mechanical side is ruled out

Related Ford codes:

U1131 on Jaguar, Volkswagen

On Jaguar, Volkswagen vehicles U1131 is documented as: SCP (J1850) invalid or missing data for fuel system. U1131 is stored when the ECU sees range or performance on the circuit named in the code. 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: Sensor reading is inside its electrical range but does not match reality; Contamination or deposits changing what the sensor sees; A mechanical fault upstream that the sensor is correctly reporting; Sensor drifted with age without failing outright.

Check first, cheapest first:

1. Compare the live value against a second sensor or a known-good figure — this code is about plausibility, not a dead circuit
2. Look for the mechanical cause first: leaks, restrictions or wear that would genuinely produce this reading
3. Clean the sensor if it is the type that fouls
4. Check freeze-frame data to see under what conditions it triggered
5. Replace the sensor only after the mechanical side is ruled out

Related Jaguar, Volkswagen codes:

U1131 on Mazda

On Mazda vehicles U1131 is documented as: Lack of fuel pump status response. U1131 points at fuel supply. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Usually one of: Fuel filter blocked; Pump worn and no longer making pressure; Pressure regulator faulty; Wiring or relay fault to the pump; Blocked strainer in the tank.

Check first, cheapest first:

1. Measure actual fuel pressure against specification — this code is about pressure, so guessing without a gauge wastes parts
2. Replace the fuel filter if it is due; it is the cheapest thing in the circuit
3. Check the pump relay and its supply voltage
4. Listen for the pump priming when the ignition is switched on
5. Replace the pump once the filter, wiring and regulator are ruled out

Related Mazda codes:

U1131 on Mitsubishi

On Mitsubishi vehicles U1131 is documented as: Display, CAN message.

Related Mitsubishi 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

U1xxx is network communication, manufacturer-specific.

Severity

Manufacturer-specific network code — a module is not answering on CAN. Check power and ground before suspecting the module.

That is what holds for U1131 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.