P1124 — Manifold Absolute Temperature Circuit High Input

For Ford vehicles

throttle position sensor a – out of self-test range

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm P1124 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the manifold absolute temperature for damage, corrosion, chafing or poor contact.
Subsystem check With the manifold absolute temperature disconnected, measure signal voltage at the harness connector: a high reading with the component unplugged indicates a short to power in the harness; if it drops to normal, the component itself is faulty.
Subsystem check Measure reference voltage, ground and signal continuity at the component connector.
Subsystem check Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P1124 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P1124 (parts and labor, USD, independent shop rates): Control module repair: $300–$1,000; Repair wiring or connectors: $80–$250; Replace the faulty sensor or actuator: $150–$500. Overall, fixing P1124 usually costs between $80 and $1,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Will P1124 clear itself?

Sometimes P1124 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

How do I diagnose P1124 myself?

Start with a scan: confirm P1124, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the manifold absolute temperature, and verify the suspect component against live data before buying parts.

What are the symptoms of P1124?

Drivers most often notice: the affected system operates intermittently or not at all, Check Engine Light on, possible limp mode depending on the affected component, increased fuel consumption in some cases.

How much does it cost to fix P1124?

Control module repair — $300–$1,000; Repair wiring or connectors — $80–$250; Replace the faulty sensor or actuator — $150–$500. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What does OBD2 code P1124 mean?

Manifold Absolute Temperature Circuit High Input (P1124): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by poor ground connection, open or shorted wiring in the circuit, corroded, loose or damaged connector.

When your vehicle's engine control unit detects a problem with the manifold absolute temperature sensor circuit, it logs trouble code P1124. This specific OBD2 designation tells you that the voltage on the MAT sensor circuit has climbed above the normal operating range — usually hovering near battery voltage instead of the expected signal. The engine control module constantly watches this circuit while you drive, comparing actual readings against pre-programmed values for your engine's temperature and load conditions.

The manifold absolute temperature sensor feeds critical data to the powertrain control module about air temperature in the intake manifold. This information influences fuel injection calculations, exhaust gas recirculation timing, and sometimes transmission shift patterns. When the sensor voltage reads artificially high for longer than acceptable, the module cannot trust the data and logs P1124. Depending on which system relies on this reading, your vehicle may compensate by using default values, switching to limp-home mode, or disabling certain functions entirely.

Symptoms

When P1124 sets, you may notice one or more of the following:

Check Engine Light illuminates on the dashboard
The engine runs roughly or idles inconsistently
Reduced engine power or hesitation during acceleration
Limp-home mode activation in severe cases
Noticeably higher fuel consumption than usual
Intermittent operation of emission-related systems

Common Causes

The most frequent culprits behind P1124 include:

Faulty manifold absolute temperature sensor producing incorrect voltage
Signal wire shorted directly to battery positive voltage
Open or damaged ground return path for the sensor circuit
Corroded, loose, or physically damaged electrical connector
Broken or chafed wiring within the sensor harness
Blown fuse supplying power to the circuit
Poor ground connection at the sensor or control module
Failed powertrain control module (less common)

Diagnostic Procedure

Follow these steps to accurately identify the root cause of P1124:

Connect an OBD2 scanner and confirm P1124 is stored, then save the freeze frame data — this snapshot of engine RPM, load, temperature, and speed at the moment of failure tells you exactly what conditions triggered the code.
Check for additional diagnostic trouble codes that may point to the underlying problem, and research any factory technical service bulletins for your specific make and model — some P0xxx codes have known fixes or software updates published by the manufacturer.
Perform a thorough visual inspection of the wiring harness and connectors associated with the manifold absolute temperature sensor, looking for damaged insulation, corrosion, broken wires, or loose fits.
Disconnect the sensor and check voltage at the harness connector — if you still read high voltage with the sensor unplugged, the harness itself has a short to power; if the voltage drops to normal reference levels, the sensor is faulty.
Verify proper reference voltage, clean ground, and signal continuity at the component connector using a multimeter.
Conduct a wiggle test on the harness while monitoring live data — any signal dropouts or fluctuations expose intermittent wire breaks.
After completing repairs, clear the code and perform a complete drive cycle matching the freeze frame conditions to verify P1124 does not return.

Repair Options and Costs

Costs vary depending on which component requires attention:

Wiring harness repair or connector replacement: $80–$250
Manifold absolute temperature sensor replacement: $150–$500
Powertrain control module repair or replacement: $300–$1,000

Most P1124 repairs total between $80 and $1,000 when you account for parts and labor at independent shop rates. An accurate diagnosis before purchasing parts prevents unnecessary spending — the most expensive fix is rarely where you should start.

Can You Drive With P1124?

In most cases, the vehicle remains drivable with P1124 stored, though you may experience diminished performance or reduced functionality of certain systems. The severity depends on how heavily your particular application relies on manifold absolute temperature data. If the car exhibits stalling, failure to start, or warning lights related to braking or steering, treat the situation as urgent and arrange towing rather than continuing to drive.