C0045 on 2007-2017 Jeep Compass: Left Rear Wheel Speed Sensor Circuit Fixes

What's Unique About the 2007-2017 Jeep Compass

The first-generation Jeep Compass and its platform-mates, the Jeep Patriot and Dodge Caliber, are highly susceptible to a specific failure that causes code C0045, especially in regions that use road salt. The design of the rear suspension exposes the wheel hub assembly to the elements. Severe rust often builds up on the hub and the thin metal clip that holds the sensor in place, causing the clip to disintegrate. This allows the sensor to become loose, creating an improper air gap with the magnetic tone ring integrated into the hub. In these common cases, simply replacing the sensor will not fix the issue; the entire wheel hub and bearing assembly must be replaced.

Generation note: The 2007-2017 model years primarily cover the first generation Jeep Compass (MK). However, the second generation (MP) was also introduced in the 2017 model year. This guide focuses on the first generation (MK49), as the common rust-related hub failure is a well-documented issue for this platform and its mates, the Patriot and Caliber.

Symptoms You May Notice

• ABS warning light is on
• Traction Control or Electronic Stability Control (ESC/ESP) light is on
• 4WD warning light may be illuminated
• Cruise control is disabled

Most Likely Causes

1. Rusted Rear Wheel Hub Assembly 🔴 High Probability → Shop Hub Assembly The design of the rear knuckle and hub on the MK platform (Compass/Patriot/Caliber) is highly susceptible to rust, which flakes off and destroys the sensor's mounting clip or damages the integrated magnetic tone ring. This is the most common point of failure in salt-belt states.
   How to confirm: Visually inspect the left rear wheel hub where the ABS sensor is mounted. Look for heavy rust buildup, a disintegrated mounting clip, or a sensor that is physically loose in its bore. If the sensor is loose or the clip is broken/missing, the hub is the cause. Forum users on Reddit frequently confirm this is the root cause.
   Typical fix: Replace the entire rear wheel hub and bearing assembly. 🎬 Watch: Step-by-step guide to replacing the rear wheel hub assembly. It is often recommended to replace the ABS sensor at the same time, as removing it from the old, rusted hub can damage it.
   Est. part cost: $70-$150
2. Failed Left Rear Wheel Speed Sensor 🟡 Medium Probability → Shop ABS Wheel Speed Sensor The sensor is exposed to harsh conditions like water, salt, and road debris, which can lead to internal failure or corrosion over time.
   How to confirm: If a visual inspection shows the hub is not severely rusted and the sensor is secure, test the sensor. Use a multimeter to check its resistance (if specs are available) or a professional scan tool to monitor its live data while spinning the wheel. A reading of zero or an erratic signal compared to other wheels indicates a failed sensor.
   Typical fix: Replace the left rear wheel speed sensor. This is a simple repair if the retaining bolt is not seized by rust.
   Est. part cost: $25-$60
3. Damaged Wiring or Connector ⚪ Low Probability
   How to confirm: Visually inspect the wiring harness from the sensor to where it enters the vehicle's body. Look for chafing, breaks, or corrosion in the connector pins. Use a multimeter to perform a continuity test between the sensor connector and the ABS module connector to find any open or shorted wires.
   Typical fix: Repair the damaged section of wire or replace the connector pigtail.
   Est. part cost: $15-$40

Rare But Worth Checking

• Failed ABS Control Module: → Shop ABS Control Module This is rare. The ABS module should only be suspected after the sensor, hub, and wiring have all been thoroughly tested and confirmed to be good. A faulty module will typically set multiple trouble codes, not just C0045.

Diagnosis Steps

1. Connect an OBD-II scanner capable of reading ABS codes to confirm C0045 is present.
2. Use the scanner's live data function to monitor the speed of all four wheels while driving slowly or spinning the wheels with the vehicle on jack stands. Confirm the left rear wheel is reading 0 MPH or has an erratic signal compared to the others.
3. Safely raise and support the vehicle and remove the left rear wheel.
4. Perform a thorough visual inspection of the wheel hub assembly where the ABS sensor mounts. Check for severe rust, a broken or missing sensor retaining clip, and see if the sensor is loose in its mounting hole. This is the most critical step for this vehicle.
🎬 See this walkthrough for replacing hubs on the Patriot platform.
5. If the hub is severely rusted and the sensor is loose, the hub assembly is the faulty part and must be replaced.
6. If the hub appears to be in good condition, inspect the sensor's wiring harness for any visible damage, chafing, or corrosion at the connector.
7. If wiring looks good, test the sensor itself. The sensors on this platform are typically active (magnetoresistive) and cannot be tested for resistance. Instead, check for a reference voltage and a changing signal.
8. If the sensor and hub seem okay, test the harness for power, ground, and signal continuity back to the ABS module.
9. After replacing parts, clear the codes with the scanner and perform a test drive to ensure the warning lights do not return.

Parts You'll Likely Need

• Rear Wheel Hub and Bearing Assembly (OEM #5105770AG, superseded by 5105770AH (Verify for 4WD vs FWD)) — This is the most common fix for a C0045 code on the Jeep Compass due to the high likelihood of rust destroying the sensor's mounting point or the integrated tone ring.
  Trusted brands: Mopar, Timken (HA590435 for 4WD), MOOG (512333 for 4WD), SKF, TRQ
  OEM price range: $180-$270
  Aftermarket price range: $70-$150
• Left Rear Wheel Speed Sensor (OEM #5105573AA) — If the wheel hub is not the cause, the sensor itself is the next most likely component to have failed due to its exposure to the elements. Note: Some parts vendors list this for the front, but it is often cited for the rear as well. Always verify fitment.
  Trusted brands: Mopar, Standard Motor Products (SMP), NTK, Delphi, Dorman (970-056)
  OEM price range: $50-$80
  Aftermarket price range: $25-$60

Related Codes That Often Appear With This One

• C1041 — This code for 'Left Rear Tone Ring Performance' points more specifically to a problem with the magnetic ring integrated into the hub, often caused by rust or damage, which is a primary cause of C0045 on this vehicle.

Technical Service Bulletins (TSBs) & Recalls

• 08-019-07

Platform-Specific Known Issues

• TSB 08-019-07 was issued for 2007 models to update ABS module software to prevent false ABS activation at startup, but it is not a direct fix for the C0045 circuit code, which is almost always a hardware failure on this platform.

Documented NHTSA Reports

While C0045 is a standard code for the left rear wheel speed sensor circuit, reports across various manufacturers highlight common failure patterns. NHTSA ODI #11219167 describes a case where the left rear wheel speed sensor encoder ring was broken, requiring replacement of both the sensor and the rear hub assembly. Similarly, NHTSA ODI #11165895 notes a service center recommendation to replace the left rear hub bearing assembly to resolve the C0045 code. In some instances, such as described in NHTSA ODI #10382746, dealers have attempted to resolve C0045 and other codes by erasing them and re-programming software. Additionally, cross-manufacturer data in NHTSA ODI #11399819 shows C0045 appearing alongside fuel system codes P0463 and P069E, though this is less common for the Jeep platform.

Mechanic-Grade Diagnostic Values

• Active Wheel Speed Sensor Voltage (Type 2 Magnetoresistive) — expected: The sensor receives a reference voltage (approx. 10.5-12V) from the ABS module. When the wheel spins, the voltage should fluctuate by a very small amount (e.g., 10.4V to 10.8V). The key is observing the change, not a specific value.. Failure: A static voltage that does not change when the wheel is spun, or no voltage at all, indicates a problem with the sensor, wiring, or ABS module.
• Active Wheel Speed Sensor Amperage (Type 2 Magnetoresistive) — expected: While spinning the wheel, the sensor's current draw should switch between approximately 7 mA and 14 mA, creating a square wave pattern when viewed on a lab scope.. Failure: A flat or erratic amperage reading indicates a failed sensor. This is a more definitive test than voltage alone.
• Passive Wheel Speed Sensor Resistance (if applicable, less common) — expected: Typically between 800 and 2,000 Ohms. However, most MK Compass/Patriot models use active sensors that will read as an open circuit (infinite resistance).. Failure: An open circuit (infinite resistance) is expected for the active sensors on this vehicle. Do not use a resistance test to condemn an active sensor.

Scan Tool Commands That Help

• wiTECH (Dealer Scan Tool): Brake Pedal Calibration — Located in the ABS module under 'Miscellaneous Functions', this should be performed after any major brake system work, though it is not directly required for a wheel speed sensor replacement.
• wiTECH (Dealer Scan Tool): Proxi Alignment Procedure — This is mandatory if the ABS control module itself is replaced. It synchronizes the new module with the rest of the vehicle's computer systems. It is found in the Body Control Module (BCM) functions.

Wiring & Ground Locations

• Anti-lock Brakes Module — Located in the engine compartment, typically on the lower right rear side.. This is the destination for the wheel speed sensor wiring. All continuity and voltage tests on the harness will terminate at this module's connector.
• G305 — A chassis ground point located in the left kick panel area, inside the cabin.. While not a direct ground for the sensor (which is grounded through the ABS module), a poor body or module ground can cause a variety of difficult-to-diagnose electronic issues, including erratic sensor behavior.
• G102 / G103 — Chassis grounds located on the top of the transmission.. These are primary engine/transmission grounds. A poor connection here can introduce electrical noise into the system, potentially affecting sensitive sensor readings.
• Rear WSS Harness Connector — The harness connector for the rear wheel speed sensor is located in the wheel well, where the sensor pigtail connects to the main body harness.. This connector is a common point for corrosion and water intrusion, which can cause an open or shorted circuit, directly triggering code C0045.

Real Owner Repair Stories

• YouTube - South Main Auto Repair (2012 Jeep Compass Latitude 2.4L) — ABS, Traction Control, and 4WD lights on. Speedometer was also reported as 'going nuts' by the customer.
  ❌ Tried (didn't work) Initial diagnosis focused on the rear wheels, as this is the most common failure point on this platform.
  ✅ What actually fixed it Live data from a test drive showed the Right Front wheel speed sensor was reading zero, and the Left Front was erratic. The issue was not the rear wheels as is common. The cause was a failed front wheel bearing/hub assembly where the integrated magnetic tone ring had failed. Replacing the front hub assembly resolved the codes.

OEM Part Supersession History

• 5105770AA, 5105770AB, 5105770AC, 5105770AD, 5105770AE, 5105770AF, 5105770AG → 5105770AH — Progressive revisions by the manufacturer to improve durability or address manufacturing changes.
  Heads up: All previous part numbers are replaced by 5105770AH. This part is listed for both Left and Right positions and fits both FWD and 4WD models within the 2007-2017 MK generation.

Model Year Variations Within This Range

• 2011-2017: The underhood fuse box layout changed with the 2011 facelift. For these later models, the relevant fuses are #33 (10A, ABS Module Power), #34 (30A, ABS Valve Power), and #35 (40A, ABS Pump Power).

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Subframe Rust/Corrosion 🔴 High — Very common, especially in rust belt regions. Can occur after 100,000 miles. Affects both front and rear crossmembers. (Ref: Chrysler extended the warranty to 10 years for this issue, but many owners report the warranty expiring before the problem becomes severe.)
• CVT Transmission Failure/Overheating 🔴 High → Shop Transmission Assembly — Common across multiple model years, particularly the 2011 model. Symptoms include whining, hesitation, and sudden loss of power, especially in hot weather or at highway speeds.
• Water Leaks into Cabin 🟠 Medium — Frequently reported issue, often caused by clogged sunroof drains, poor seam sealing at the A-pillar, or a bad windshield seal. (Ref: A dealer communication (STAR Case S1823000053) exists to help technicians diagnose A-pillar leaks, but it is not a recall.)
• Suspension Component Failure (Control Arms, Tie Rods) 🟠 Medium — Premature failure of control arm bushings and tie rods is a common complaint, often occurring at relatively low mileage (around 60,000 miles).
• Totally Integrated Power Module (TIPM) Failure 🔴 High — A known issue on 2007 models, causing a wide range of bizarre electrical problems like lights flashing, horn honking randomly, and no-start conditions.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used wiring harness pigtail from a junkyard can be a cost-effective repair if only the connector is damaged and the donor vehicle is from a dry, non-rust-belt climate. A complete used hub assembly is generally not recommended due to the high failure rate and the difficulty of assessing the condition of the internal bearing and integrated tone ring.

Donor-vehicle mileage cap: roughly under 80000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• For a wiring pigtail, ensure the plastic is not brittle and the locking tab is intact.
• Check for any signs of corrosion (green or white powder) on the connector pins.
• Ensure there is at least 6-8 inches of wire attached to allow for splicing.
• For a hub, check for zero play or roughness when spinning by hand (though this is not a guarantee of a good tone ring).

Aftermarket brands forum-validated for this vehicle:

• Timken
• MOOG
• SKF

Brands owners have reported issues with on this vehicle:

• Unbranded, 'white box' parts from online marketplaces are a gamble. While some may work, they have a higher reported failure rate and may not have the same durability as established brands, especially concerning the quality of the magnetic tone ring.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• C0035 — Right front wheel speed sensor circuit; similar failure mode involving sensor or wiring damage from road debris.
• C0040 — Right rear wheel speed sensor circuit; shares the identical rust-prone hub and mounting clip design as the left rear (C0045).
• C0031 — Left front wheel speed sensor circuit; often diagnosed alongside rear codes when inspecting the ABS system for erratic signals.
• U0121 — Lost Communication with Anti-Lock Brake System (ABS) Control Module; can be related to the electrical issues seen in 2007 models with TIPM failures.

Frequently Asked Questions