Car diagnostics in Stevenage
Warning light on, or something just does not feel right? We use top-of-the-range Bosch KTS diagnostic equipment to find the real fault, not just read a code. You get a plain-English answer and a quote before any repair work starts.
All makes and models | 5-star Google rating | 12-month guarantee on repairs | Unit 8, Chells Industrial Units, Stevenage SG2 0LQ
What diagnostics do we do in Stevenage?
TGPP-Autocare is an independent garage at Unit 8, Chells Industrial Units, Stevenage SG2 0LQ. We use Bosch KTS diagnostic equipment to scan all modules and read live data on all makes and models. We diagnose engine management and warning lights, DPF and AdBlue faults, electrical faults, transmission, ABS and traction control, airbag and SRS, air conditioning, and immobiliser and key programming issues. We also do pre-purchase inspections on used cars. We have one master diagnostic technician, so complex jobs can have a wait. Call 01438 232556 and we will tell you honestly how long.
Bosch KTS equipment
We run top-of-the-range Bosch KTS diagnostics, not a cheap plug-in reader. That means we can read every module in the car, watch live sensor data while the engine runs, and test components properly.
But equipment only gets you part of the way. A fault code tells you where to look, not which part has failed. Our master technician does the investigating that turns a code into the real cause.
A quick word on wait times
We have one master technician doing our diagnostic work. A straightforward fault code scan is usually quick, but complex or intermittent faults take time and the wait for those can be long.
We would rather tell you that now than leave you waiting. Call or WhatsApp us with your make, model and symptoms and we will give you an honest idea of timing before you book.
What we diagnose
We cover everything diagnostics-related. Every check starts with a clear explanation of what we are looking for, and nothing further is done without your approval.
Fault code check
The starting point for almost every investigation. We scan every module, not just the engine.
- Full multi-system scan
- Stored and pending fault codes read and explained
- Live data on key sensors
- Written report and quote for any repair
Engine performance
Misfires, poor economy, rough idle or a loss of power, pinpointed with live data rather than guesswork.
- Fuel trim and mixture analysis
- Misfire and cylinder balance testing
- Injector and ignition testing
- MAF, MAP and lambda sensor analysis
DPF diagnostics
Reduced power, higher fuel use or a DPF light. We find out why it is blocking, not just that it is.
- Soot load and back-pressure testing
- Forced regeneration where appropriate
- DPF cleaning or replacement if needed
- Underlying causes: short journeys, oil contamination, sensor faults
AdBlue and SCR
AdBlue faults can trigger a countdown to no-start and an MOT emissions failure. Worth sorting early.
- NOx sensor testing and replacement
- AdBlue pump and dosing unit diagnostics
- Tank level sensor testing
- SCR catalyst assessment and AdBlue top-up
Electrical faults
Modern cars are as much computer as car. We test from the battery through to individual modules and wiring.
- Battery, charging and alternator testing
- Body control module diagnostics
- Wiring and continuity testing
- Parasitic drain testing
Transmission
Slipping, rough shifts or a gearbox warning light. Misdiagnosed gearbox work is expensive, so we test first.
- Gearbox fault code scan
- Fluid pressure testing
- Solenoid and valve body testing
- Clutch pack and torque converter assessment
ABS and traction control
These share sensors and modules. If the light is on, the system may not work in an emergency stop.
- Wheel speed sensor testing
- ABS pump, modulator and module diagnostics
- ESP and stability control diagnostics
Airbag and SRS
An airbag light means the system may not deploy in a crash. It should never be reset without finding the cause.
- SRS module fault code scan
- Sensor and clock spring testing
- Seat belt pretensioner diagnostics
- Module replacement and coding
Air conditioning
Not blowing cold, or smells odd? We diagnose first so you are not paying for parts that are not the problem.
- Leak detection and pressure testing
- Compressor and clutch checks
- Electrical and control testing
- R134a and R1234yf regas
Keys and immobiliser
Lost or damaged keys, fob faults or a car that will not start because of the immobiliser.
- Immobiliser diagnostics
- Key fob programming
- Transponder key coding
- ECU and BCM security coding
Call with your make, model and year to confirm we can do your car.
Pre-purchase inspection: buying a used car?
A car that looks great can hide thousands of pounds of faults. We give you a full diagnostic picture before any money changes hands.
- Full multi-system scan, including hidden and pending fault codes
- Engine live data: misfires, fuel trims and sensor health
- Battery and charging test, plus brake, ABS and suspension check
- Written report with any faults found and what they are likely to cost, so you can buy with confidence or renegotiate
Got a warning light on?
Do not ignore it, and do not panic. Most warning lights mean something specific that our equipment can identify straight away. These are the ones we see most.
Engine management
Oil pressure
Coolant temperature
Charging system
Brake system
ABS
Brake pad wear
DPF
Glow plug
EPC
ESP
Tyre pressure
Oil level
SuspensionOil pressure (red)
Low oil pressure can destroy an engine very quickly. Stop safely as soon as you can and do not drive on.
Coolant temperature (red)
The engine is overheating. Pull over safely, switch off and let it cool. Do not open the coolant cap. Call us.
Brake warning
Could be low brake fluid, a handbrake issue or a serious fault. Brakes are your main safety system, so do not ignore it.
Engine management
The most common light. It can mean anything from a loose fuel cap to a serious fault. Get it scanned promptly.
Battery and charging
A problem with the battery, alternator or charging system. The car can cut out without warning if you ignore it.
ABS
ABS may not work in an emergency stop. Normal braking usually still works, but get it diagnosed soon.
DPF
The filter is blocked or a regeneration has failed. A longer motorway run can sometimes clear it. If the light stays on, get it scanned.
Airbag / SRS
The airbags may not deploy in a crash. This is safety-critical, so do not ignore it or have it reset without finding the cause.
Tyre pressure
A tyre is well under-inflated or a sensor has failed. Check pressures first. If the light stays on, we can reset or replace the sensors.
Glow plug (diesel)
If it stays on after starting, a glow plug has probably failed. That means hard cold starts and rough running.
Got a light on right now? Call 01438 232556 or WhatsApp us a photo of the dash with your make and model, and we will tell you how urgent it is.
Why get your diagnostics done with us
TGPP-Autocare is run by Tom and Pat. Good diagnostic work is about experience and honesty as much as equipment.
We interpret, not just read
Any garage can read a code. We cross-check it against live data, sensor behaviour and your symptoms to find the real cause, not just the symptom.
Plain-English results
We do not hand you a printout and leave you to Google it. We tell you what each fault means, what happens if you leave it, and what it costs to fix.
No unnecessary repairs
We only recommend what is needed, we quote before any work starts, and nothing is done without your approval.
Honest about timing
We have one master technician. We will tell you upfront if there is a wait, rather than promising a quick turnaround we cannot keep.
Repair it here too
Once we have found the fault we can usually fix it at the same garage, with a 12-month parts and labour guarantee on the repair.
Spread the cost
If the fix is a big one, we offer 0% finance through PaymentAssist, no minimum spend, over 3 to 9 months.
See also: car repairs, DPF and AdBlue, cooling systems, car servicing, MOTs and warranty repairs.
Car diagnostics questions
Tap a question to open the answer.
We connect our Bosch KTS equipment to your car, scan every module for stored and pending fault codes, and look at live sensor data. Then we investigate to find the real cause, because a fault code does not tell you which part has failed. We explain what we found in plain English and quote for any repair before work starts.
A straightforward fault code scan is usually quick. Complex or intermittent faults take longer. We have one master diagnostic technician, so the wait for complex jobs can be long. Call 01438 232556 or WhatsApp us your symptoms and we will give you an honest idea of timing before you book.
Yes. We diagnose all makes and models using Bosch KTS equipment. That covers engine, transmission, ABS, airbag, electrical, air conditioning, DPF, AdBlue and immobiliser systems.
It depends on the light. A red oil pressure, brake or coolant temperature warning means stop safely as soon as you can and do not carry on. An amber engine management light usually means you can drive carefully to a garage, but it should be scanned promptly. If you are unsure, call us before you drive.
The price depends on what needs investigating, and we confirm it when you book. Any repair that follows is quoted separately before we start, and nothing is done without your approval.
Yes. We scan for fault codes, test soot load and back-pressure on DPFs, and test NOx sensors, AdBlue pumps, dosing units and tank sensors. We find the underlying cause first, then quote for cleaning, repair or replacement.
Yes. Our pre-purchase inspection includes a full multi-system scan with hidden and pending fault codes, live engine data, battery and charging tests, and a brake, ABS and suspension check, with a written report.
Yes, across most popular makes and models: key fob programming, transponder coding and immobiliser diagnostics. Call us with your make, model and year and we will confirm we can help.
Unit 8, Chells Industrial Units, Chells Way, Stevenage, SG2 0LQ. We are open Monday to Friday 8am to 6pm, and Saturday by appointment. We look after drivers from Stevenage, Hitchin, Letchworth, Knebworth, Welwyn Garden City, Hertford and Baldock.
Find us in Stevenage
TGPP-Autocare Ltd
Unit 8, Chells Industrial Units
Chells Way, Stevenage
Hertfordshire, SG2 0LQ
01438 232556 (phone and WhatsApp)
Opening hours
- Monday to Friday: 8:00am to 6:00pm
- Saturday: by appointment, please call
- Sunday: closed