Poor connection or corrosion at the MAF sensor connector (loose, bent or contaminated terminals); Open circuit, high resistance or chafed wiring in the MAF ground wire between sensor and control module; Faulty or contaminated MAF sensor; Poor engine or body earth point affecting sensor reference grounds; Air leak or intake restriction causing an implausible air flow reading alongside the ground fault; Fault inside the engine control module.

P1104

Mass Air Flow Sensor Circuit Ground.

Jaguar
Powertrain
Manufacturer code
Medium severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
1: AreaFuel and air metering
04: FaultThe specific fault in that area

What it means

On Jaguar, P1104 points to a fault in the ground circuit of the mass air flow (MAF) sensor. The engine control module saw a ground reference or sensor signal that did not match what it expects, for example a voltage offset on the ground line or a MAF reading that does not make sense for the engine load. Because the MAF reading is used to calculate fuelling, the fault can affect running quality. The exact circuit layout and pin numbers depend on the model and engine, so check the wiring diagram for the specific vehicle.

Symptoms

Malfunction indicator lamp on
Rough or unstable idle
Hesitation or poor throttle response
Poor fuel economy
Engine running in a reduced-performance or limp mode
Hard starting or occasional stalling

Possible causes

Poor connection or corrosion at the MAF sensor connector (loose, bent or contaminated terminals)likely
Open circuit, high resistance or chafed wiring in the MAF ground wire between sensor and control modulelikely
Faulty or contaminated MAF sensorpossible
Poor engine or body earth point affecting sensor reference groundspossible
Air leak or intake restriction causing an implausible air flow reading alongside the ground faultpossible
Fault inside the engine control modulerare

How to diagnose

Read all stored and pending codes and note any other air flow, fuelling or sensor supply codes, then review freeze frame data.
Visually inspect the MAF sensor, its connector and the wiring loom for damage, chafing, oil contamination, water ingress or corrosion.
Check the intake pipework between the air filter box and throttle for splits, loose clamps or leaks, and check the air filter condition.
With the engine running, view live MAF data and compare it with expected values at idle and under load; check it responds smoothly to throttle changes.
Disconnect the connector and check terminals for tightness and corrosion, then test the ground wire for continuity and resistance back to the control module using the wiring diagram.
Measure the voltage drop on the sensor ground and supply circuits with the circuit loaded; wiggle the harness to look for intermittent faults.
Inspect and test the main engine and body earth connections for tightness and corrosion.
If wiring and earths are good, test or substitute the MAF sensor according to the manufacturer procedure, and only then consider the control module.

How to fix

Clean, repair or replace the corroded or damaged MAF connector and terminals.
Repair or replace the damaged MAF ground wiring, ensuring proper soldered and sealed repairs or a new section of loom.
Replace the MAF sensor if it is faulty or tests out of specification.
Clean and refit loose or corroded earth connections, using the correct fixings.
Repair intake leaks or replace split hoses and fit a new air filter if blocked.
Repair or replace the engine control module only after all other causes have been ruled out, following the manufacturer procedure.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but poor fuelling control may cause stalling, poor running and higher fuel use. Get it diagnosed soon to avoid further problems or damage to the catalytic converter.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.