PCS warning on your Corolla, C-HR or RAV4, often paired with a 'Headlight System Malfunction' message? They share the same windscreen camera, so when one's off the other usually is too. Here's what's actually triggering both, the Toyota-specific camera-and-radar pair behind the system, and what the calibration costs.
You can drive the car. The Pre-Collision System and the rest of the Toyota Safety Sense suite stay offline while the warning's showing. The system won't intervene if traffic stops sharply ahead. Normal brakes, steering and conventional cruise all still work. Leave more following distance until it's sorted.
Toyota's Pre-Collision System uses a windscreen-mounted camera and a millimetre-wave radar behind the front grille, working together. Both feed PCS, Dynamic Radar Cruise Control and Lane Tracing Assist. The camera also runs Automatic High Beam. Here's what we see disturbing them.
On Toyota, the windscreen camera that backs up PCS is the same camera that handles Automatic High Beam. If PCS is flagging and 'Headlight System Malfunction' is showing alongside it, that's one root cause. The camera's aim is off, and both systems flag the loss of confidence together.
Because the camera is glued into the windscreen, a new windscreen always moves it. Toyota's PCS calibration after a glass swap is a separate step that most windscreen fitters don't carry kit for. PCS faults appearing within a few drives of a new windscreen are the trigger we see most on the Corolla.
Toyota's millimetre-wave radar sits behind the front grille. A repaired or refitted bumper, a new grille, even a knock that took the bumper off briefly is enough to shift the radar's aim. PCS, Dynamic Radar Cruise and the broader TSS suite all read from it.
On Toyota, PCS depends on both sensors agreeing with each other. After a front-end impact, the radar may have shifted and the camera may have shifted independently. A workshop calibrates both in the same visit, against a manufacturer-spec target for the camera and a separate radar target for the front sensor.
Trolley contact in a car park, a curb strike on the lower bumper trim, a hard parking sensor brush. None of those leave visible damage, but any of them can shift the radar bracket enough to throw the fault. Worth a slow walk round the bumper before booking anything.
Toyota Safety Sense has shipped in several generations: TSS 2.0 on the 2019-2022 Corolla, TSS 3.0 on the 2023-on Corolla, RAV4 and C-HR. Each generation has a slightly different camera position and a different target board specification. If the workshop calibrates against the wrong target for your car's year, the calibration won't hold. Worth flagging your registration year when you book.
If the trigger was a real impact, the camera bracket or the radar housing may be cracked, not just shifted. Calibration won't hold on damaged hardware. A diagnostic scan tells you which case you're in before any work is booked.
Worth checking first: confirm the windscreen camera area is clean and the camera bracket isn't visibly skewed (look up at it from the driver's seat). If PCS is still showing, both the camera and the radar typically need recalibrating.
On a Toyota that means static calibration of the windscreen camera against a manufacturer-spec target board, followed by static calibration of the front radar against a separate radar target. The procedure runs through Toyota Techstream or a compatible diagnostic platform.
It's a fixed £349 through our network for the radar tier, which covers up to three ADAS systems including the camera and the auto-high-beam. The full-system reset is £499 if multiple modules need clearing at once. If the scan shows the camera or radar was damaged in the original impact, you'll know the cost before any work goes ahead. The full procedure is in our ADAS calibration guide.
Pricing is fixed across our network. Same price wherever you are in the UK. Your tier is set by what work has been done, not by your postcode or your car's make.
All prices include the diagnostic scan, the calibration procedure (static, dynamic, or both as required), a post-calibration check, and a calibration certificate. No charge for diagnostic if you decide not to proceed.
Send your registration and a line on what's happened. We'll come back with the fixed price, the nearest accredited workshop, and the soonest available slot.
Because they share the same camera. The windscreen-mounted camera on a Toyota runs Pre-Collision System and Automatic High Beam from the same image feed.
When the camera's aim is off, both systems flag the loss of confidence at the same moment. It looks like two faults but it's one underlying cause. A single calibration visit usually clears both.
PCS calibration sits in our £349 tier, which covers up to three ADAS systems in one visit. That's the windscreen camera, the front radar, and any related modules like Automatic High Beam or Lane Tracing Assist. If multiple modules need clearing at once after a collision, the Full System Reset at £499 covers everything. Same price wherever you are in the UK.
Toyota Safety Sense (TSS) is the umbrella name for Toyota's ADAS suite. Pre-Collision System (PCS) is one feature inside TSS, the automatic emergency braking and forward collision warning side. Lane Tracing Assist, Dynamic Radar Cruise and Automatic High Beam are the other TSS features. When PCS flags a fault, the underlying camera or radar that's off is often shared with the other TSS features, which is why several warnings can appear together.
No. Any workshop with Toyota Techstream-compatible diagnostic equipment and a calibration bay can do it, and our accredited network is set up for that. The dealer will charge their own labour rate for the same procedure. The certificate we issue is accepted by insurers and sits on the car's service history.
Toyota PCS uses a windscreen-mounted camera. New glass is the top trigger we see.
Bumper work disturbs the front radar that pairs with the PCS camera. Common follow-on.