U060B means the powertrain control module (PCM) lost the digital conversation with turbocharger or supercharger boost sensor A. The U prefix is the whole story: this is a network code, not a circuit code. The classic boost sensor codes, P0235 through P0238, describe an analog voltage that drifted out of range. U060B describes a message that stopped arriving on schedule. The sensor may be perfectly healthy and simply unheard.
Severity: moderate. Can you keep driving? Yes, gently, for a short distance. When the PCM loses the boost reading it stops trusting the turbo system, so most calibrations cut boost or command a reduced-power mode. The engine still runs on a substitute pressure value derived from throttle position and engine speed. Expect flat acceleration and a wrench or check engine light. There is no immediate danger to the engine, but towing or highway merging with no boost is unpleasant enough that most owners have this looked at within days.
Which engines can even set this code
An analog boost sensor cannot lose communication, because it never communicates. It returns a voltage between roughly 0.5 and 4.5 V on a signal wire, and a fault in that wire sets P0237 (low) or P0238 (high). U060B exists only where the boost sensor is a smart sensor with a small circuit board that digitizes the pressure reading and sends it to the PCM as a stream of messages.
The sensors that do this on current vehicles:
- Ford EcoBoost engines from about 2017 on, including the 2.3 L in the Ranger, Bronco and Explorer, the 2.7 L and 3.5 L in the F-150, and the 3.0 L in the Explorer and Lincoln models. Ford combines the turbocharger boost pressure (TCBP) reading with charge air cooler temperature (CACT) in one sensor on the intake tube after the intercooler. Owner reports of U060B on the 2019 Ranger 2.3 L are the most common online, and a JustAnswer Ford technician working one of those trucks lists the connector checks in the diagnostic section below.
- Porsche 991.2 and later turbocharged flat-sixes, where a Rennlist thread on the 991 forum documents U060B stored by the DME after a boost sensor connector problem.
- Audi and Volkswagen 2.9 L and 3.0 L TFSI engines on the B9 platform, where U060B appears in VCDS scans alongside other charge-air codes.
If the vehicle is not one of these, and the boost sensor has a plain three-wire analog connector, a scan tool showing "U060B" is usually a translation error by the tool. Read the code again with the manufacturer's own definition table. Some generic tools map manufacturer-specific codes onto the SAE list and produce a definition that does not match the vehicle. The same trap applies to the whole U06xx range, which the SAE reserved for lost communication with individual smart sensors.
What the PCM actually detects
The digital boost sensor sends its reading many times per second, each message carrying a checksum. The PCM sets U060B when messages stop arriving for a calibrated window (typically one to two seconds), or when a run of messages fails the checksum. Two consequences follow:
- The fault is either present or it is not. A lost message is binary. Unlike a range/performance code, there is no "slightly wrong" reading to interpret. That makes the live data test below very clean: either the boost pressure parameter updates or it freezes.
- A momentary loss counts. A connector that opens for two seconds on a rough road, then reconnects, will set U060B, clear the active fault, and leave a stored code with a freeze frame. Pull the freeze frame before clearing anything. Engine speed, load and vehicle speed at the moment of the fault tell you whether it happened at idle, under boost, or bouncing over a driveway lip, and that points at the harness section to flex first.
Because the PCM uses boost pressure to protect the engine from over-boost, most calibrations respond to U060B by limiting wastegate or bypass valve duty so the turbo cannot build meaningful pressure. That is why the symptom is lost power rather than a subtle hesitation. On Ford trucks the message is usually "Powertrain Malfunction / Reduced Power."
Causes, in the order they are found
A connector that has worked loose or let water in. The combined boost and temperature sensor sits on the intake tube in the airflow at the front of the engine, where it takes road spray from the front and vibration from the tube. On the 2019 Ranger, the JustAnswer technician's first instruction was to unplug and reseat the connector, then clear codes with a scan tool and retest, because a partially seated connector is the most common way this code appears on a truck with no other complaint. Look for green or white corrosion on the terminals, a terminal pushed back out of the connector body, or a seal that no longer grips the wire.
A chafed or broken wire in the intake tube harness. The harness to the sensor moves with the intake tube every time the engine rocks. Where it crosses an edge, a bracket or a tie point it wears through. The insulation may look intact while the copper inside is broken, which gives an intermittent that only appears under load. The freeze frame usually shows this as a fault at higher engine speed and load, when the engine rocks most.
Loss of power or ground to the sensor. A digital sensor needs its supply to run the electronics. On the Ranger the technician gives the pin assignment: 5-volt reference on pin 3, ground on pin 2, signal on pin 1. No reference voltage means a fuse, a splice, or an upstream short on a circuit that also feeds other sensors, and the sensor is not the problem. Ford EcoBoost engines of this era are known for poorly crimped harness splices, and a bad splice on the shared reference circuit will take several sensors down at once.
Low system voltage. A battery that dips hard during a cold crank can reset the sensor electronics just as the PCM starts listening. When U060B appears together with several other U codes after the vehicle has sat, test the battery and charging system before touching anything else. The same reasoning applies to every U code on the vehicle: several devices do not fail at once, but their shared power can.
The sensor itself. It does fail, and when it does the code is usually solid rather than intermittent, and the live boost pressure reading stays frozen at a fixed value or at zero with the engine running. Oil mist in the intake tube from a saturated crankcase breather can contaminate the sensing element over time.
The PCM. Last on every manufacturer's list, and only after the wiring has passed every test and the fault returns with a known-good sensor after a complete drive cycle.
A diagnostic order that does not waste a sensor
- Record before clearing. Note whether U060B is current or history, which codes sit beside it (P0237, P0238, P0299 for underboost, other U codes), and the freeze frame. If a flashing light is present, that is a misfire, not this code; see why a flashing light means stop.
- Watch the boost pressure parameter live. Start the engine and watch TCBP or boost pressure on the scan tool. A reading that tracks throttle blips is a healthy link with an intermittent fault somewhere; a reading stuck at one value with the code current is a live loss.
- Reseat the connector, then clear and retest. Unplug it, look at both halves with a light, plug it back until it clicks, clear the code, and drive. On the 2019 Ranger this was the technician's first step, and on a fair number of trucks it is also the last.
- Check reference and ground at the connector, key on. Roughly 5 V on the reference pin and under 0.1 V of drop on the ground pin. No reference means the fault is upstream, and replacing the sensor cannot fix it.
- Wiggle-test the harness with the engine running. Flex the harness along the intake tube, at the bracket and at every tie point while watching live boost pressure. A dropout while flexing pinpoints the damaged section.
- Check the signal wire end to end. Continuity should be under an ohm from sensor connector to PCM connector, with no short to ground or to the reference wire. Water in the connector typically shorts the signal to an adjacent pin rather than opening it.
- Only then substitute a sensor, and confirm with a full drive cycle so the readiness monitors complete. If the code returns on a known-good sensor with clean wiring, the PCM is finally a suspect.
What U060B does not tell you
The code names the device that went quiet, not the reason. It does not separate a wet connector from a dead sensor from a blown fuse, and it does not say whether the fault is present right now. Live data and the connector do that. The sensor sits last on the list because it is the one component that can be tested by observation instead of replaced on faith; the general principle is covered in what a trouble code does not tell you.
Frequently asked questions
Can I drive with a U060B code?
Yes, for short distances at moderate speed. The PCM limits boost when it loses the sensor, so the engine feels weak but is not at risk. Do not tow or drive long highway distances in reduced-power mode, and do not leave it for weeks, because the intermittent that caused it usually gets worse.
Will a new boost sensor fix U060B?
Only when the sensor has actually failed, which is the least common cause. On the vehicles that set this code most often, the fault is a loose or wet connector, a chafed harness or a lost reference voltage. Check those first. A sensor replaced without those checks often leaves the code in place.
Why does U060B appear with P0299 or P0237?
Once the PCM loses the boost message it substitutes a value, and that substitute can trip the analog plausibility checks and the underboost monitor at the same time. All of these codes point at the same connector and harness. Fix the communication fault first and the others usually do not return.
How much does it cost to fix U060B?
Reseating a connector costs nothing. A wiring repair is usually under an hour of labor. The combined boost and temperature sensor on a Ford EcoBoost is a modest part with a few minutes of labor. The expensive outcome is a PCM, which the manufacturer procedures list last and only after a full drive cycle with a known-good sensor and verified wiring.
Related codes
- P0235 / P0236: boost sensor circuit and range or performance. Set by an analog sensor reading badly, not by a lost message.
- P0237 / P0238: boost sensor circuit low or high. On digital sensors these can be set at the same moment as U060B because the substitute value trips the plausibility check.
- P0299: turbocharger underboost. Follows U060B when the PCM limits boost as a protective response.
- U060C: lost communication with boost sensor B on twin-turbo engines with two sensors.
- U0100 and other U01xx / U02xx codes: lost communication with other modules. Several at once means shared power, ground or bus wiring.
The code number itself tells you the family and the domain; how to read an OBD2 code number explains what each character means.