U0418 Code: Invalid Data Received From Brake System Control Module
Brake-control data such as pedal position or brake-assist status looks implausible to another module.
Unverified: this manufacturer-specific definition comes from a single source or varies by model. Confirm it with a brand-specific scan tool.
Stop driving
If the red brake warning is on, the pedal feels hard, sinks further than normal or the car displays reduced brake assist, don't drive it; have it towed. With only an amber warning and a normal pedal, drive gently straight to a shop and leave extra stopping distance.
Safety first · Consult a professional
- Braking system affected: ABS may be disabled. Drive carefully and have it checked promptly.
At a glance
Severity: High
- Meaning
- Invalid Data Received From Brake System Control Module
- System
- Module Communication · Network
- Safe to drive?
- With caution
- Typical repair cost
- $120–$3,500
- DIY difficulty
- Hard
U0418 is set when a module such as the PCM, hybrid control, cruise/radar or transmission module gets messages from the brake system control module that fail its plausibility checks. On many newer vehicles, especially hybrids, EVs and some late-model trucks, this is a separate or integrated unit that runs an electric brake booster or brake-by-wire system, measures pedal travel and blends regenerative with friction braking; on other vehicles the term simply overlaps with the ABS module. Because the definition in service information varies by manufacturer, this page is marked unverified. What the brake module reports, such as brake pedal applied, driver deceleration request and boost status, is used for cruise control, start-stop, shift interlock and collision braking, so bad data disables several features at once.
How to read U0418
- U Network
- 0 Generic (SAE)
- 4 Module Communication
- 18 Specific fault
Symptoms
- Red brake warning or 'Service brake assist / Reduced brake assist' message
- Brake pedal feels harder or travels further than usual
- Regenerative braking off on hybrids and EVs, stronger engine or motor drag missing
- Adaptive cruise, automatic emergency braking and auto start-stop unavailable
- Shifter won't come out of Park or push-button start behaves oddly because the brake signal isn't trusted
- Several warnings appear after a battery was drained or replaced
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Low or unstable 12-volt supply; electric boosters and brake-by-wire units shut down or report invalid data during voltage dips
- Brake module software fault or mismatch after another module was updated
- Brake pedal travel/position sensor or brake switch sending an implausible signal
- Loose, corroded or water-damaged connector or fuse at the brake module or booster
- Replacement brake module or booster not configured or not calibrated
- Internal failure of the brake control module or electric booster
Diagnosis step by step
Check pedal feel and fluid level first
With the engine or ready mode on, press the brake pedal: it should be firm and stop high. Check the brake fluid is between MIN and MAX; a low level or soft pedal is a hydraulic problem that must be fixed before any network diagnosis.
Tools: Flashlight
Read the brake module's own codes
Scan every module and open the brake system module (on some vehicles listed as EBCM, brake booster or ECB). Pedal sensor, booster motor or supply voltage codes stored there explain U0418 and set the repair order.
Tools: OBD-II scanner
Load-test the 12-volt battery
Brake-by-wire systems are sensitive to voltage. Look for 12.6 V at rest, 13.5 to 14.7 V running, and a load or conductance test that passes; on hybrids and EVs the small 12-volt battery is a frequent culprit.
Tools: Multimeter
Watch pedal position data
Monitor brake pedal position or travel and the brake switch status while slowly pressing and releasing the pedal. Values should rise and fall smoothly and agree with each other; a jump or a switch that doesn't change state points to the sensor.
Tools: OBD-II scanner
Inspect connectors and fuses
Check the brake module and booster connectors for corrosion or pushed-out pins, and verify their fuses, including the high-current booster fuse, with a meter.
Tools: Multimeter, Flashlight
Update and recalibrate
A dealer or equipped shop should check for brake module software updates and run the pedal sensor and booster calibration routines after any repair or battery work. Confirm the fix with a test drive using normal and firm stops.
Tools: OBD-II scanner
Where the parts are
- 1Battery
- 2Alternator
- 3Engine computer (ECM)
- 4CAN bus
- 5Transmission
- 6Wheel speed sensor
- 7High-voltage battery
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Replace 12-volt battery (incl. registration where needed) | Yes | $180–$450 |
| Brake module software update and calibration | No | $150–$350 |
| Replace brake pedal position sensor or brake switch | No | $120–$400 |
| Repair connector or wiring at brake module | No | $150–$500 |
| Replace brake control module or electric booster | No | $1,200–$3,500 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Field data
| Ford | 3 | Escape Hybrid | |
|---|---|---|---|
| Jeep | 2 | Cherokee |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Depends
U0418 rarely affects the emissions test by itself, but a lit red brake or ABS warning fails the safety inspection in states that have one, and is unsafe regardless.
Frequently asked questions
How is the brake system control module different from the ABS module?
On vehicles with an electric brake booster or brake-by-wire, the brake module handles pedal feel, brake apply and regenerative blending, while ABS handles wheel-slip control. Some manufacturers combine both in one unit, which is why the code's exact target depends on the vehicle.
Can a weak 12-volt battery really cause a brake code?
Yes. Electric boosters draw a lot of current and their modules watch supply voltage closely; a weak battery can make them report invalid data or reduce assist. On hybrids and EVs, test the 12-volt battery before anything else.
Why won't my car shift out of Park with this code?
The shift interlock needs a trusted 'brake applied' signal. If the brake module's data is flagged invalid, the transmission may not accept it and keeps the shifter locked.
Is it safe to keep driving?
Only if the pedal feels completely normal and no red brake warning is on, and then only to a shop. Any change in pedal feel or a reduced brake assist message means stop and tow.
Sources
- SAE J2012 – Diagnostic Trouble Code Definitions
- ISO 15031-6 – Road vehicles, diagnostic trouble code definitions (EOBD)
- Manufacturer public service information (cross-checked)
- NHTSA Complaints API
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