U0418 on 2017 Jeep Renegade: Brake System Data Error Causes and Fixes

What's Unique About the 2017-2017 Jeep RENEGADE

Jeep vehicles, including the Renegade, are known to be highly sensitive to battery voltage. A weak or failing battery can cause numerous communication codes, including U0418, to appear without any actual component failure. This is often due to the high electrical demands of modern systems. Technical Service Bulletin (TSB) 18-078-22 explicitly states that U0418 can be set erroneously if the battery voltage drops below 10 volts. The provided NHTSA TSBs for the 2017 Renegade list U0418 alongside a variety of other seemingly unrelated codes, which often points to a central electrical, network, or PCM software issue rather than a specific part failure.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• ABS warning light is on
• Traction control or Electronic Stability Control (ESC) light is on
• Check Engine Light (Malfunction Indicator Lamp) is on
• Cruise control may be disabled
• "Service 4WD System" message may appear
• "Service Hill Start" message may appear.
• In some cases, the vehicle may not shift out of Park.

Most Likely Causes

1. Low Battery Voltage or Failing Battery 🔴 High Probability Jeep platforms are notoriously sensitive to low voltage. A Technical Service Bulletin for this platform (18-078-22) explicitly states that U0418 can be set erroneously if the battery voltage drops below 10 volts. The Renegade's complex electrical system can trigger a cascade of communication faults when the battery is weak, often leading to a dashboard full of warning lights.
   How to confirm: Perform a load test on the battery. A simple voltage check is not enough. Most auto parts stores can do this for free. Voltage should remain above 11.5V when tested under load. Also inspect the battery terminals and the Intelligent Battery Sensor (IBS) on the negative terminal for tightness and corrosion.
   Typical fix: Replace the 12-volt battery. Ensure the replacement is the correct type (often AGM) and size.
   Est. part cost: $150-$300
2. Faulty Wheel Speed Sensor 🟡 Medium Probability Wheel speed sensors are exposed to heat, moisture, and debris, making them a common failure point. A faulty sensor can feed implausible data (e.g., reading a fixed high speed when stopped) to the ABS module, which then sends this invalid data to other modules, triggering U0418. Forum users on related Jeep platforms frequently cite a bad wheel speed sensor as the cause.
   How to confirm: Use an advanced scan tool to monitor live data from all four wheel speed sensors while driving. A sensor that drops out, shows erratic readings, or doesn't match the others is faulty. Often, a wheel-speed-specific code like U140A will accompany U0418, pointing to the problem sensor.
   Typical fix: Replace the faulty wheel speed sensor. This is a common DIY repair.
   Est. part cost: $40-$100
3. Damaged Wiring or Connectors 🟡 Medium Probability Wiring to wheel speed sensors or the main ABS module can be damaged by road debris, corrosion, or chafing. Forum users on Jeep Wrangler forums report finding broken, corroded, or unpinned wires at the sensor connector or a few inches up the harness, which then causes code U0418.
   How to confirm: Visually inspect the wiring harness leading to each wheel speed sensor and the main connector at the ABS module. Pay close attention to the area where the harness flexes with suspension travel. Check for chafing, breaks, or green/white corrosion on the connector pins. A continuity test from the sensor connector to the ABS module connector can confirm a broken wire.
   Typical fix: Repair the damaged section of the wiring harness or replace the connector pigtail. It is often recommended to replace the entire sensor harness rather than splicing, as improper repairs can introduce resistance and cause future issues.
   Est. part cost: $20-$80
4. Failing ABS Control Module ⚪ Low Probability While less common, internal failure of the ABS module can cause it to generate and transmit corrupt data. This should be the last item to suspect after all other causes are ruled out.
   How to confirm: This is a process of elimination. If the battery, all sensors, and all wiring are confirmed to be good, the module itself is the likely culprit. This diagnosis is best left to a professional with OEM-level diagnostic tools who can attempt to re-flash the module before condemning it.
   Typical fix: Replace the ABS control module. This part must be programmed to the vehicle's VIN by a dealership or a qualified shop with the correct tools.
   Est. part cost: $400-$1200

Rare But Worth Checking

• PCM Software Glitch: On some Jeep models, a software glitch in the Powertrain Control Module (PCM) can cause this code. TSB 18-016-17 REV. B specifically applies to the 2017 Renegade with the 2.4L engine and lists U0418 as one of several codes that can be resolved by reprogramming the PCM with the latest software.

Diagnosis Steps

1. Check for other DTCs. Note all codes present, as they can provide clues (e.g., a specific wheel speed sensor code like U140A).
2. Fully charge and load test the battery. This is the most critical first step for any Jeep with communication codes. A voltage drop below 10V can trigger this code.
3. If the battery is healthy, inspect the battery terminals and main ground connections for tightness and corrosion. Clean them thoroughly.
4. Using an advanced scan tool, view the live data stream from the ABS module. Watch the wheel speed sensor readings while driving to check for any that are erratic, read an impossible speed, or drop to zero.
5. Visually inspect the wiring harness and connectors for all four wheel speed sensors and the main ABS module connector. Look for any signs of damage, corrosion, or loose pins. Pay special attention to the harness section near the wheel that flexes.
6. If a specific wheel speed sensor is suspected, check for continuity and resistance in its wiring back to the ABS module connector. A YouTube video by 'What The Duck Auto' demonstrates this process on a Renegade.
7. If all sensors and wiring are confirmed good, check for any available PCM or ABS module software updates. TSB 18-016-17 REV. B is a known PCM update for the 2017 Renegade that addresses this code.
8. If all other possibilities are exhausted, the ABS module itself is the most likely cause of the failure. This requires professional diagnosis and replacement.

Parts You'll Likely Need

• Battery — Low voltage is a very common trigger for this communication code on Jeep vehicles, as confirmed by TSB 18-078-22.
  Trusted brands: Mopar, Deka, Interstate
  OEM price range: $200-$350
  Aftermarket price range: $150-$300
• Wheel Speed Sensor (OEM #68372700AA (Rear), 68246922AA (Front)) — These sensors provide the primary data to the ABS module. A faulty sensor sending bad data is a frequent cause.
  Trusted brands: Mopar, Bosch, NTK, Standard Motor Products
  OEM price range: $70-$120
  Aftermarket price range: $40-$80
• ABS Control Module (OEM #52062978) — If all other components are good, the module itself may have failed internally. This part is expensive and requires programming.
  Trusted brands: Mopar
  OEM price range: $600-$900
  Aftermarket price range: $400-$700

Related Codes That Often Appear With This One

• U140A — Implausible Right Front Wheel Speed Signal Received. This code directly points to a specific wheel speed sensor circuit as the source of the invalid data, making diagnosis much easier.
• P0703 — Brake Switch 2 Performance. This code is directly related to the brake system and often appears with U0418, as seen in TSB 18-016-17 REV. B.
• U1424 — Implausible Engine Torque Signal Received. This is another communication code, indicating network data integrity issues, often triggered by the same root cause as U0418 (like low voltage or a software glitch). It is also cited in TSB 18-016-17 REV. B.
• P0101 — Mass Air Flow Sensor Circuit Performance. While seemingly unrelated, its appearance with network codes in TSB 18-016-17 REV. B suggests a widespread electrical or module communication problem that can be resolved with a PCM update.
• P0128 — Thermostat Rationality. Like P0101, its presence with U0418 in TSB 18-016-17 REV. B points towards a broader electrical or network fault.

Technical Service Bulletins (TSBs) & Recalls

• FCA TSB 18-016-17 REV. B (NHTSA ID: 10121810): Titled 'Flash: Powertrain Diagnostic and System Enhancements', this bulletin applies to the 2017 Renegade with 2.4L engine. It involves reprogramming the PCM to fix an issue where a MIL is illuminated and codes including U0418, U1424, P0101, P0128, and P0703 may be stored.
• FCA TSB 18-078-22: While for a later model year, this TSB is highly relevant as it explicitly states 'DTC U0418 can be set erroneously due to a low battery (below 10 volts)', confirming the platform's sensitivity to battery voltage.

Platform-Specific Known Issues

• The provided NHTSA TSBs (#1805520, #1801617) show that code U0418 is often logged along with a cluster of other engine and network codes, indicating a potential systemic electrical issue rather than a single failed part. The actual FCA TSB number for the 2017 Renegade is 18-016-17 REV. B, which calls for a PCM software update to fix this issue.
• A real-world repair story on a Jeep Gladiator forum detailed how a shorted wire in the rear differential locker harness caused code U0418 along with a cascade of other 4WD and traction system warnings, highlighting how seemingly unrelated wiring faults can trigger this code.

Mechanic-Grade Diagnostic Values

• CAN Bus Network Resistance — expected: < 60 Ω. Failure: A reading significantly higher than 60 Ω (often 120 Ω) indicates an open circuit or a missing terminating resistor. A reading near 0 Ω indicates a short between CAN high and CAN low wires.
• ABS Module Power Supply Voltage — expected: 11.5 - 13.5 V. Failure: Voltage below 11.5V (especially below 10V) with the ignition on can cause the module to send invalid data and trigger the U0418 code.
• CAN High and CAN Low Voltage (Key On, Engine Off) — expected: Approx. 2.5V each. Failure: Significant deviation from 2.5V on either line, or voltages that do not add up to approximately 5V, indicates a bus problem, short, or faulty module pulling the voltage down.
• Passive Wheel Speed Sensor Resistance — expected: Compare a suspect sensor to a known-good one on the same axle; readings should be very close (within ~10%). A generic expected range is 800-2350 Ω.. Failure: An open circuit (infinite resistance) or a short (near zero resistance) indicates a failed sensor. A value significantly different from the sensor on the other side of the vehicle also indicates failure.

Scan Tool Commands That Help

• wiTECH or compatible (Appcar DiagFCA): Proxi Configuration Alignment — This procedure is mandatory after replacing the ABS control module. It synchronizes the new module with the vehicle's other computers. Failure to perform this will cause persistent communication codes and a flashing odometer.
• wiTECH: Reprogram the PCM — Used to apply software updates as specified in TSBs like 18-016-17 REV. B. This can resolve the U0418 code if it's caused by a known software glitch, particularly on 2017 models built between June and September 2017.
• wiTECH or advanced scan tool: ABS Static and Dynamic Tests — These are bidirectional tests that command the ABS pump and valves to cycle. This can help verify the functionality of the ABS hydraulic unit after electrical faults have been ruled out.

Wiring & Ground Locations

• Star Connector (CAN Bus Hub) — On related modern Jeep platforms, this is a central connector hub located on the passenger side, often behind the glove box or kick panel. It serves as the junction for all CAN bus wiring.. For network-wide communication issues, this is a central diagnostic point. A technician can disconnect modules one by one from this hub to isolate which one might be shorting out the entire network.
• ABS Module Ground — While a specific Renegade diagram was not found, a common location for the main ABS module ground on Jeeps is under the driver's seat or on the chassis frame rail near the module itself. For example, some diagrams show a G304 ground point under the driver's seat.. A poor or corroded ground connection to the ABS module can cause it to malfunction and send invalid data, directly leading to a U0418 code.
• Under-hood Fuse Box (Power Distribution Center) — Located in the engine compartment.. This box contains the primary fuses for the ABS system, including power for the module, pump, and valves. On the related Jeep Compass, these are fuses #33 (10A), #34 (30A), and #35 (40A). Checking these fuses is a fundamental step.

Real Owner Repair Stories

• JLwranglerforums.com user 'Deezus' and another member (Jeep Wrangler JL (related modern platform)) — ABS and traction control lights on, codes U0418 and U1409 (Implausible Left Front Wheel Speed Signal).
  ❌ Tried (didn't work) Initial diagnosis was unclear.
  ✅ What actually fixed it The final fix was a broken wire at the left front ABS sensor harness. Another user with the same codes found a wire had become 'unpinned' from the plastic connector plug at the sensor.

When the Usual Fixes Don't Work

• While common causes point to the battery or the wheel speed sensor itself, forum reports from owners of modern Jeeps emphasize the need for meticulous wiring inspection. In one documented case, the final fix for U0418 was not a faulty part, but a single wire that had broken inside the harness near the sensor connector, and in another, a pin had backed out of the connector shell. This highlights that replacing sensors without first testing and inspecting the harness can lead to misdiagnosis. Furthermore, a fault in a seemingly unrelated module, like the power steering pump, can short the communication network and cause the ABS module to report invalid data, demonstrating that the problem isn't always within the brake system itself.

OEM Part Supersession History

• 68231552AA → 68248188AA — Part revision or manufacturer change.
  Heads up: This is a generic electrical connector for the 2017 Renegade. While not confirmed to be for the ABS module specifically, it shows that wiring components have been updated and using the correct, latest part number is important for repairs.

Model Year Variations Within This Range

• 2017 (Specifically builds from 06/22/2017 to 09/07/2017): Vehicles built within this specific date range equipped with the 2.4L engine may have a PCM software issue. TSB 18-016-17 REV. B was released to fix an issue where U0418 and a host of other codes would set erroneously. The fix is to reprogram the PCM with updated software, not replace any hardware.