What Does P0122 Mean on a 2023 Honda Ridgeline?
Code P0122 on your 2023 Honda Ridgeline tells you the Engine Control Module has detected a Throttle Position Sensor signal that has collapsed below approximately 0.2 volts — far below the normal operating range of 0.5 to 4.5 volts. This is not a performance issue or a gradual drift in sensor accuracy. It is a hard circuit fault that signals complete or near-complete loss of throttle position data, and the ECM responds by activating limp mode immediately.
The 2023 Ridgeline is a refresh of the 2nd generation truck platform (launched 2017, refreshed 2021), powered by a 3.5L V6 i-VTEC engine producing 280 horsepower paired with a 9-speed automatic transmission. This engine and throttle body architecture is shared with the 2023 Honda Pilot and Passport, meaning the TPS circuit design and common failure modes are well-documented across the Honda lineup. The TPS is integrated into the throttle body assembly — it is not a separately serviceable component.
At just 1-2 years old, a P0122 on a 2023 Ridgeline is relatively uncommon but not unheard of. Production variability in connector seating, early throttle body defects, and harness routing issues during assembly are the most likely culprits at this age. The good news: your truck is almost certainly still within warranty.
Symptoms You Will Notice
P0122 is not subtle. The ECM's protective response to a failed TPS circuit creates symptoms that are immediately obvious and often alarming:
- Check Engine Light and Reduced Power warning: Honda's instrument cluster will display a Reduced Engine Power message alongside the amber check engine indicator. In some cases, the VSA (Vehicle Stability Assist) warning may also illuminate due to the ECM's reduced confidence in throttle data.
- Dramatic loss of acceleration: The truck may feel like it is towing a heavy load even with nothing attached. Engine RPM may be electronically capped, and the transmission may refuse to downshift normally.
- Rough or stumbling idle: Without accurate throttle position data, the ECM struggles to maintain stable idle speed. You may notice the engine hunting for idle or stalling when coming to a stop.
- Hesitation on throttle input: Pressing the accelerator produces a delayed, sluggish response rather than the immediate torque the 3.5L V6 normally delivers.
- Intermittent symptoms before code sets: Some owners report brief hesitation or power loss episodes before P0122 stores permanently — these are early clues that the TPS circuit is degrading.
If you experience these symptoms while towing a trailer or carrying cargo in the bed, pull over safely and do not continue until the truck has been inspected. A throttle control failure under load creates a genuine safety risk.
Most Likely Causes on a 2023 Ridgeline
At 1-2 years of age, the cause profile shifts compared to older trucks. Early-life failures point toward production and assembly issues rather than wear-and-tear corrosion:
- Connector seating or production variability (38-40% likelihood): The throttle body electrical connector may not have been fully seated during manufacturing or during a prior dealer service. A connector that appears latched but is not fully engaged can allow the signal voltage to drop to near-zero under engine vibration. This is the first thing a technician should check — and it is a warranty-covered correction.
- TPS internal defect (33-35% likelihood): Early manufacturing defects in the throttle body assembly can cause the TPS element to fail shortly after the truck enters service. Honda has issued Technical Service Bulletins (TSBs) on throttle body assemblies for related platforms — ask your dealer to check for open TSBs against your VIN.
- Wiring harness routing issue (18% likelihood): If the engine wiring harness was routed against a sharp edge, bracket, or heat source during assembly, abrasion or heat damage can develop quickly in the first year. Inspect the harness segment between the throttle body and the main engine wiring junction.
- ECM software or calibration issue (5-7% likelihood): In some cases, early software on a new model year's ECM can misinterpret valid TPS readings as out-of-range. A dealer software update or reflash may resolve the code without any hardware repair.
- Moisture intrusion (2% likelihood): Early connector seal failures or improper repair of the connector boot can allow water ingress, especially on a truck used in wet climates or washed frequently.
Repair Costs and Warranty Coverage
The best news for 2023 Ridgeline owners: Honda's 3-year/36,000-mile bumper-to-bumper warranty almost certainly covers this repair at zero cost to you. Your 2023 truck is 1-2 years old and very likely under 36,000 miles. All of the probable causes — connector defect, throttle body failure, harness issue, or ECM software update — are covered under this warranty when present from the start or occurring during normal use.
Do not attempt DIY repairs or visit an independent shop before exhausting your warranty coverage. Unauthorized repairs can complicate warranty claims. The correct first step is scheduling a dealer appointment and requesting a Honda HDS diagnostic scan to pull the full fault data.
If, for any reason, the truck is out of warranty coverage, here are the realistic repair costs:
- Connector inspection and reseating: $50-$100 — Often a 30-minute service call at a dealer or independent shop. No parts cost if no damage is found.
- Throttle body replacement: $340-$550 — OEM assembly is $180-$280 in parts; labor is 1.5-2 hours. After replacement, the Honda idle relearn procedure must be performed: key ON for 10 seconds without starting, then start and idle undisturbed for 10 minutes.
- Wiring harness repair: $150-$350 — Depends on location and extent of damage.
- ECM software update: $0-$150 — TSB-covered updates are free at the dealer. Non-TSB calibrations may carry a diagnostic fee.
Urgency and Next Steps
P0122 requires immediate attention regardless of the truck's age or warranty status. Limp mode makes the Ridgeline unsafe to use as a work truck, tow vehicle, or highway commuter. Contact a Honda dealer today, describe the check engine light and power loss symptoms, and request a priority diagnostic appointment. Mention code P0122 specifically so the service advisor can allocate proper technician time.
Given your warranty coverage, the financial exposure here is minimal — but the safety risk of ignoring the code is not. Get it diagnosed now.
How AutoDetective AI Can Help
AutoDetective's AI can analyze your 2023 Ridgeline's P0122 code against Honda's known production failure patterns, helping you understand whether your truck matches a documented TSB pattern before your dealer appointment. Enter your VIN for a free diagnosis report, cost estimates, and warranty status check.