U0415 on 2014-2019 Chevrolet Impala: Invalid ABS Data Causes and Fixes

What's Unique About the 2014-2019 Chevrolet IMPALA

The 10th generation Chevrolet Impala (2014-2019) is specifically called out in manufacturer bulletins for having a unique vulnerability. The instrument panel wiring harness, specifically the Data Link Connector (DLC) branch, is prone to being pinched behind the dash during assembly. This creates a high-resistance short that can trigger U0415 and a host of other seemingly unrelated communication codes. This makes a wiring fault a much higher probability on this car than on other vehicles. Additionally, a PSCM calibration error can cause U0415 to persist after a simple event like a battery replacement, requiring a dealer software update to fix.

Diagnostic Flowchart

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

Symptoms You May Notice

• "Steering Assist Is Reduced" message in the Driver Information Center (DIC).
• ABS warning light on.
• Traction Control or StabiliTrak warning light on.
• Increased effort required to turn the steering wheel.
• Check Engine Light may be illuminated.
• Service Brake Assist message may appear.

Most Likely Causes

1. Pinched Instrument Panel (IP) Harness 🔴 High Probability This is a documented factory assembly issue for the 2014 Impala, as detailed in GM Technical Service Bulletins PIC5894 and PIC5894A. The harness can get caught behind the IP carrier bracket, typically on the driver's side.
   How to confirm: Scan for other communication codes listed in the TSBs (e.g., U0073, U0121, U0151). Physically inspect the harness behind the left side of the instrument panel (near the driver's knee bolster) for signs of pinching or damage. The TSB notes it can be difficult to see without loosening the IP bracket.
   Typical fix: Loosen the instrument panel carrier, free the harness, and repair any chafed or broken wires using solder and heat shrink or appropriate connectors. Reroute the harness to prevent future damage.
   Est. part cost: $5-$25
2. Faulty Wheel Speed Sensor or Wiring 🟡 Medium Probability → Shop ABS Wheel Speed Sensor The ABS module relies on wheel speed sensor data. If a sensor fails or its wiring is damaged (a common issue from road debris or during brake work), it sends junk data to the ABS module, which then broadcasts that invalid data, triggering U0415 in other modules like the PSCM.
   How to confirm: Scan for wheel speed sensor-specific codes (e.g., C0035, C0040, C0050). Use a scan tool to monitor live data from all four wheel speed sensors while driving. The faulty sensor will show an erratic or zero reading. Visually inspect the sensor wiring for breaks or corrosion, especially where it flexes with steering. 🎬 Watch: A walkthrough of the ABS sensor harness replacement.
   Typical fix: Replace the faulty wheel speed sensor and/or its harness pigtail. 🎬 Watch: How to replace a faulty wheel speed sensor. The sensor is part of the wheel hub assembly on some models but is often available separately.
   Est. part cost: $30-$80
3. Faulty ABS Control Module (EBCM) ⚪ Low Probability → Shop ABS Control Module While less common than wiring issues, the module itself can fail internally, causing it to send corrupt data packets onto the CAN bus.
   How to confirm: This is a process of elimination. If all wiring (including the pinched harness area), grounds, and sensor inputs to the ABS module are confirmed to be good, but U0415 persists, the module itself is the likely culprit.
   Typical fix: Replace the ABS control module. This often requires programming with a GM-specific tool (TIS2WEB) to match the vehicle's VIN and configuration.
   Est. part cost: $250-$700
4. Low Battery Voltage or Poor Grounds ⚪ Low Probability → Shop Vehicle Battery All control modules, especially the electric power steering system, are sensitive to voltage. A weak or dying battery, or a failing alternator, can cause modules to malfunction and send invalid data, triggering a cascade of communication codes including U0415.
   How to confirm: Test the battery voltage with the engine off (should be >12.4V) and while running (should be 13.5V-14.5V). A professional load test is recommended. Inspect and clean the main battery terminals and chassis ground points.
   Typical fix: Replace the battery or alternator if they fail testing. Clean or repair ground connections.
   Est. part cost: $150-$500

Rare But Worth Checking

• Incorrect Steering Angle Sensor Calibration: If a wheel alignment or steering component replacement was recently performed, an improper steering angle sensor relearn procedure can cause the Power Steering Control Module to receive data it considers invalid, setting U0415. This is documented in TSB PI0800A for other GM vehicles on a similar platform.
• Power Steering Control Module (PSCM) Calibration Error: → Shop Power Steering Control Module TSB PIT5593A describes a scenario where a temporary fault (like a disconnected battery) sets U0415, but a software glitch prevents the code from moving to 'history' status after the issue is resolved. It remains a 'current' code, triggering the steering message on every startup. The fix is not a part replacement, but a PSCM software update performed by a dealer.

Diagnosis Steps

1. Scan all vehicle modules for DTCs. Note all codes, especially any other U-codes or C-codes, and whether they are 'current' or 'history'.
2. If multiple communication codes from the list in TSB #PIC5894A are present, immediately prioritize inspecting the instrument panel harness for pinching behind the IP carrier.
3. If U0415 is paired with C056D and a steering message, follow the diagnostic path in TSB #19NA182.
4. If U0415 is paired with a wheel speed sensor code (like C0050), inspect the wiring and connector for that specific sensor before doing anything else.
5. Check battery health with a load tester and verify charging system voltage (13.5V-14.5V) to rule out power supply issues.
6. If the code appeared after a battery change or disconnection and will not clear, consult a dealer about performing the PSCM software update mentioned in TSB PIT5593A.
7. Visually inspect the main wiring harness connector at the ABS module for corrosion or damage.
8. If all wiring and sensor inputs appear correct, use an advanced scan tool to monitor the live data stream from the ABS module. Look for illogical readings.
9. If all external factors are ruled out, the ABS module itself becomes the primary suspect.

Parts You'll Likely Need

• Front Wheel Speed Sensor (OEM #23483145 (replaces 22831244)) — The sensor or its integrated harness is exposed to the elements and suspension movement, making it a common failure point that sends invalid data, triggering U0415.
  Trusted brands: ACDelco, Dorman, Delphi
  OEM price range: $40-$60
  Aftermarket price range: $25-$50
• Rear Wheel Speed Sensor (OEM #23483152 or 23483151) — Similar to the front, failure of a rear wheel speed sensor will cause the ABS module to broadcast invalid data.
  Trusted brands: ACDelco, SKP
  OEM price range: $45-$65
  Aftermarket price range: $30-$55
• ABS Control Module (EBCM) (OEM #84092230 (replaces 22760041, 23227339, 23234105 for models w/o adaptive cruise)) — This is the module sending the invalid data. It is replaced only after all wiring and sensor inputs have been confirmed to be good. Requires programming.
  Trusted brands: ACDelco (Genuine GM)
  OEM price range: $400-$700
  Aftermarket price range: $250-$500 (Remanufactured)

Related Codes That Often Appear With This One

• C056D — This code for 'Electronic Control Unit Hardware' is specifically mentioned alongside U0415 in TSB #19NA182 related to the 'Steering Assist is Reduced' message.
• U0121 — This means 'Lost Communication With ABS Module'. It can appear with U0415 if the communication issue is severe, such as a completely severed wire in the pinched harness mentioned in TSB #PIC5894A.
• C0035 / C0040 / C0050 — These are wheel speed sensor circuit codes (Front Left / Front Right / Rear Right). A fault in a wheel speed sensor can be the root cause, sending bad data to the ABS module, which in turn triggers U0415.
• U0073, U0077, U0151, etc. — A large group of U-codes appearing together strongly indicates a major network wiring problem, such as the pinched instrument panel harness described in TSBs PIC5894 and PIC5894A.

Technical Service Bulletins (TSBs) & Recalls

• 19NA182: Addresses a 'Steering Assist Is Reduced' message when U0415 and/or C056D are set.
• PIC5894A: Details the inspection for a pinched DLC branch in the IP harness causing multiple U-codes, including U0415.
• PIC5894: The original version of the pinched harness bulletin.
• PIT5593A: Explains a PSCM calibration error that keeps U0415 as a 'current' DTC, requiring a software update.

Platform-Specific Known Issues

• TSB #PIC5894A and #PIC5894 document a known issue where the instrument panel harness can be pinched behind its carrier, causing U0415 and many other communication codes.
• TSB #19NA182 directly links U0415 to the 'Steering Assist Is Reduced' message, confirming the data relationship between the ABS and Power Steering modules on this vehicle.
• TSB #PIT5593A highlights a software issue where the Power Steering Control Module (PSCM) fails to clear a current U0415 code after a temporary fault, requiring a dealer re-program.

Mechanic-Grade Diagnostic Values

• High-Speed CAN Bus Network Resistance — expected: Approximately 60 Ohms between Pin 6 (CAN-H) and Pin 14 (CAN-L) at the DLC with the battery disconnected.. Failure: A reading of ~120 Ohms indicates an open circuit or a module/terminating resistor is offline. A reading near 0 Ohms indicates a short between the CAN high and low lines.
• CAN Bus Voltage (Key On, Engine Off) — expected: CAN High (Pin 6) should be ~2.7V. CAN Low (Pin 14) should be ~2.3V.. Failure: Voltages that are stuck high, low, or match each other indicate a bus problem like a short to power or ground.
• EBCM Ground Resistance — expected: < 1.0 Ohm between the EBCM ground wire terminal at the connector and a clean chassis ground point.. Failure: High resistance indicates a poor ground connection, which can cause the module to behave erratically and send invalid data.

Hidden / Shadow Codes Worth Checking

• U0415 with Symptom Byte $5A: The '$5A' symptom byte specifies 'Invalid/Irrational Data'. This tells the technician that the module is communicating, but the data it's sending doesn't make logical sense (e.g., reporting wheel speed when the vehicle is known to be stationary). (see via GM GDS2 (Global Diagnostic System 2) or equivalent high-end scan tool that can read manufacturer-specific symptom bytes.)

Scan Tool Commands That Help

• GM GDS2: Module Diagnostics > EBCM > Data Display — To view live data from all four wheel speed sensors simultaneously to identify an erratic or non-reporting sensor, which is a common root cause for U0415.
• GM GDS2: Module Diagnostics > PSCM > Module Information — To confirm if the Power Steering Control Module (PSCM) is the module logging U0415, which is common. This helps verify that the PSCM is the 'victim' of the bad data, not the source.
• GM GDS2: SPS (Service Programming System) — To perform the software update on the Power Steering Control Module (PSCM) as described in TSB PIT5593A, which fixes the glitch where U0415 remains a 'current' code after a temporary fault like a battery disconnect.

Wiring & Ground Locations

• G103 / G105 — G103 is on the cowl, above the brake booster. G105 is at the left front of the engine compartment behind cooling fan relays.. The EBCM, BCM, and Instrument Panel Cluster (IPC) rely on these grounds. A poor connection at G103 can disrupt communication between modules, while a poor ground for the EBCM itself (often near G105 on the frame rail) can cause it to send corrupt data, triggering U0415.
• Instrument Panel Harness (DLC Branch) — Behind the instrument panel carrier, on the driver's side of the dashboard.. This is the specific location for the pinched harness issue described in TSBs PIC5894 and PIC5894A. Damage here directly impacts the CAN bus wiring, causing a flood of communication codes including U0415.
• EBCM Connector — At the Electronic Brake Control Module, typically located on the ABS hydraulic unit in the engine bay.. This is the main data and power connection for the ABS module. Corrosion from moisture or backed-out pins can cause the module to lose power or send corrupted data over the CAN bus.

Real Owner Repair Stories

• YouTube user 'The Mechanic' (2017 Chevrolet Impala) — Steering assist was being shut down by the car's computer.
  ❌ Tried (didn't work) A 'reputable shop' told the owner the Power Steering Control Module was bad and needed replacement.
  ✅ What actually fixed it The technician found codes U0415-71, C0800-5A, and C0050-04 (Right Rear Wheel Speed Sensor Circuit Open). A visual inspection revealed the right rear wheel speed sensor wire had been cut/pinched, likely during a previous wheel hub replacement. Replacing the $50 ABS sensor cable resolved all codes and restored power steering function.
• ImpalaForums user discussion (2014 Chevrolet Impala) — 'Steering Assist is Reduced' message, multiple communication codes including U0415.
  ❌ Tried (didn't work) Replacing the battery., Replacing the ABS module.
  ✅ What actually fixed it A dealership technician identified and repaired the pinched instrument panel wiring harness as described in TSB PIC5894A. The repair involved accessing the harness behind the dash, repairing chafed wires, and rerouting it to prevent future damage. The repair took approximately 3 labor hours.

OEM Part Supersession History

• 22760041, 23227339, 23234105 → 84092230 — Standard part evolution for reliability improvements and component updates.
  Heads up: This part number is for models WITHOUT adaptive cruise control. All replacements, regardless of part number, require online programming via GM's Service Programming System (SPS) to configure the module to the specific vehicle's VIN and options.

Model Year Variations Within This Range

• 2014-2019: No significant variations have been identified for this specific fault. The underlying Global A electrical architecture and the physical instrument panel structure remained consistent, meaning the pinched harness vulnerability (TSB PIC5894A) and the PSCM software glitch (TSB PIT5593A) apply to the entire generation.