P2620
Throttle Position Sensor D Circuit LowP2620 is a generic OBD-II powertrain diagnostic trouble code: Throttle Position Sensor D Circuit Low. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P2620 means
P2620 indicates that the PCM has detected a voltage below the expected minimum threshold on the signal circuit of throttle position sensor D. Modern drive-by-wire throttle bodies often contain multiple TPS sensors (commonly labeled A through D) for redundancy and cross-validation. Sensor D is typically a secondary or tertiary sensor used to confirm the primary sensor reading.
A low-circuit condition usually points to a short to ground on the TPS signal wire, an open in the sensor reference voltage supply, or a failed sensor element. Because the PCM compares multiple sensor outputs and expects them to track together within calibrated limits, a single sensor reporting out of range will trigger a fault even if the throttle is physically moving correctly.
When P2620 is active the PCM may limit throttle authority or engage a reduced-power mode to prevent uncontrolled throttle response. The driver may notice sluggish acceleration or a power reduction. Diagnosis involves checking wiring integrity and sensor supply voltages before condemning the throttle body assembly.
Common causes
Most-frequently reported root causes when P2620 is logged.
-
1
Short to ground on the TPS D signal wire.
-
2
Open circuit in the 5-volt reference supply to TPS D.
-
3
Broken or corroded ground wire at the throttle body sensor connector.
-
4
Failed TPS D potentiometer or hall-effect element inside the throttle body.
-
5
Corroded or loose throttle body harness connector pins.
-
6
Water intrusion into the throttle body sensor cavity.
-
7
PCM internal reference voltage fault affecting sensor D supply.
Symptoms drivers notice
How to diagnose P2620
A typical diagnostic flow when this code is present.
-
1
Retrieve all DTCs and freeze-frame data with a scan tool; note whether other TPS codes (A, B, C) are also present.
-
2
Inspect the throttle body harness connector for corrosion, spread pins, or moisture damage.
-
3
With the key on, measure the 5-volt reference voltage at the TPS D supply pin; absence of reference voltage points to a wiring or PCM issue.
-
4
Backprobe the TPS D signal wire and observe voltage throughout the throttle sweep to identify shorts or open circuits.
-
5
Check the signal wire for continuity and absence of short to ground from the throttle body connector to the PCM.
-
6
Compare TPS A, B, C, and D live values on a scan tool; divergence of sensor D confirms it as the fault point.
-
7
Replace the throttle body assembly if sensor wiring checks out and the sensor element is confirmed faulty.
Related powertrain codes
Frequently asked questions
Can I replace just sensor D, or do I need the whole throttle body?
On most applications TPS sensors are integral to the throttle body housing and are not serviceable separately; the entire throttle body is typically replaced.
Is P2620 the same as P0122?
P0122 covers TPS A circuit low and is a more common code; P2620 specifically applies to sensor D, which is a supplementary sensor on dual- or quad-sensor throttle bodies.
Could a dirty throttle body cause P2620?
Carbon buildup can affect throttle plate movement but is unlikely to cause a circuit-level low-voltage code; P2620 is primarily an electrical fault.
Will the throttle body need relearning after replacement?
Yes. Most drive-by-wire throttle bodies require a throttle position relearn procedure via scan tool or a specified key-cycle routine after replacement.
Disabling P2620 in software
RaceTune can permanently disable P2620 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
ECUs with a P2620 disable in our catalogue
Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.
- Bosch MD1CS001 verified 1 software version
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
Got P2620 in your scan?
Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.
Upload your file