What Does P0122 Mean on a 2021 Honda CR-V?
A P0122 code on your 2021 Honda CR-V tells you that the engine control module has measured a voltage of less than 0.2 volts from the throttle position sensor signal circuit — a value so low it is outside the range of any legitimate throttle position reading. The TPS normally operates between 0.5 and 4.5 volts as the throttle plate moves from fully closed to wide open. When the ECM sees a sub-threshold voltage, it concludes the circuit has broken down electrically, not that the throttle is simply in an unusual position.
The 2021 CR-V is in its 5th generation, offered in the 1.5L turbocharged VTEC gasoline configuration or the CR-V Hybrid with Honda's 2.0L Atkinson-cycle engine and two-motor electric system. In both cases, throttle control is fully electronic — drive-by-wire — meaning the TPS is the only pathway through which the ECM knows what the driver is commanding with the accelerator pedal. A failed TPS circuit leaves the ECM flying blind.
Investigating P0122 on this generation CR-V means following two tracks simultaneously: the electrical connector and wiring between the ECM and throttle body, and the throttle body assembly itself where the TPS is permanently integrated.
Symptoms of P0122 on the 2021 Honda CR-V
The symptoms of P0122 are serious and can escalate quickly. Drivers investigating this code on their 2021 CR-V should expect some or all of the following:
- Sudden Check Engine Light — often appearing without warning and accompanied by the VSA (Vehicle Stability Assist) warning light
- Limp mode engagement — throttle output severely restricted, vehicle may refuse to accelerate beyond 20–30 mph
- Stalling at idle — especially common when coming to a stop at traffic signals or in slow-moving traffic, creating a hazardous situation
- Throttle hesitation or non-response — pressing the accelerator produces a delayed, weak, or completely absent response
- Rough, hunting idle — the engine surges up and down looking for a stable idle point without valid throttle position data
- Hard starting — in some cases the ECM's protective logic makes the engine difficult to restart after stalling
The 1.5L turbo CR-V's engine bay is tightly packaged, and the turbocharger generates significant heat near the throttle body area. This thermal environment can accelerate wear on wiring insulation and connector seals, making heat-related wiring damage worth investigating early in the diagnostic process.
Top Causes of P0122 on the 2021 Honda CR-V
Our diagnostic investigation ranks the following causes from most to least likely:
- Throttle body connector corrosion or pin damage (40% of cases) — The electrical connector at the throttle body is exposed to engine heat, vibration, and in northern climates, road salt contamination. Corroded pins or a damaged connector body can drop signal voltage below the ECM's minimum detection threshold. This is the first place to investigate before ordering any parts.
- Integrated TPS failure within the throttle body (32% of cases) — Honda integrates the TPS into the throttle body as a non-serviceable unit. An internal short, open circuit, or carbon contamination around the throttle plate sensor track can cause a fixed low-voltage output. Honda HDS software can display live TPS voltage data to confirm whether the fault is internal or external.
- Wiring harness damage (15% of cases) — The wiring between the throttle body and ECM passes through several routing points where chafing can occur. On the 1.5L turbo, heat from the turbocharger intercooler plumbing can also damage wiring insulation. A systematic inspection of the full harness run is required.
- ECM 5-volt reference circuit fault (10% of cases) — The ECM provides a 5-volt reference to the TPS. If this reference line is shorted to ground anywhere in the circuit — or if the ECM itself has a damaged output driver — all sensors on that reference circuit will report artificially low voltages. Checking reference voltage at the connector with a digital multimeter is a key diagnostic step.
- Moisture or water intrusion (3% of cases) — A failed cowl drain, cracked grommet, or pressure-wash damage can introduce water into the TPS circuit wiring, causing intermittent or sustained low-voltage readings.
Estimated Repair Costs for the 2021 Honda CR-V
Repair costs depend entirely on which component has failed. Here is what to expect:
- Connector cleaning and terminal repair: $50–$150 at an independent shop with Honda experience
- Throttle body replacement (1.5L turbo): $310–$510 parts and labor combined; OEM is strongly recommended due to pre-calibrated TPS values
- Wiring harness repair: $150–$350 depending on damage location and length of repair needed
- ECM diagnosis, reprogramming, or replacement: $200–$500+ depending on root cause
Always request a proper HDS-assisted diagnosis before authorizing parts replacement. Misdiagnosis on TPS circuit faults is common and expensive.
Urgency and Warranty Guidance for 2021 CR-V Owners
P0122 demands immediate attention. Do not continue driving a vehicle that cannot reliably control its own throttle. The safety risk is real and the code will not resolve itself.
For the 2021 CR-V, basic warranty coverage status depends on your mileage and purchase date. If you are still within Honda's 3-year/36,000-mile bumper-to-bumper coverage or 5-year/60,000-mile powertrain warranty, the dealer should cover this repair at no cost. Even if basic warranty has expired, the federal 8-year/80,000-mile emissions warranty covers emissions-related sensors and the ECM — the throttle control system often qualifies. Verify your exact warranty status before paying out of pocket.
After any throttle body or connector work, perform Honda's required idle relearn procedure: ignition ON for 10 seconds (do not start), then start and idle for 10 uninterrupted minutes.
How AutoDetective AI Can Help
AutoDetective's AI platform can analyze the full picture of your 2021 CR-V's diagnostic data — not just the P0122 code in isolation. By evaluating accompanying codes, freeze frame data, and known failure patterns for this generation and engine, AutoDetective delivers a ranked diagnosis and location-specific repair cost estimates, so you approach the shop or dealer with clarity and confidence.