Caterham Vx P1C99 Engine Trouble Code
What is Caterham Vx P1C99?
When Caterham Vx P1C99 code appears, first check your gas cap. Pull over safely, ensure it is tight, and inspect for cracks. A loose or damaged gas cap affects fuel-system pressure and emissions. A replacement cap costs about $3–$10. This simple fix can resolve the code and improve fuel economy.
P1C99 on the Caterham Vx
Transmission-mounted speed sensors on the Caterham Vx share a ground path with the engine control module. A corroded ground point on the transmission bell housing generates electrical noise that the ECU misinterprets as a P1C99 fault condition.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Vehicle: | Caterham Vx |
| Brand: | Caterham |
| Model: | Vx |
| Code: | P1C99 |
P1C99 Caterham Vx Symptoms
Check Engine Light
Illuminated Caterham Vx dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Caterham Vx
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Caterham Vx
Increased Emissions
Failed emissions test due to P1C99
P1C99 Code Structure
Understanding what each digit means in the P1C99 powertrain trouble code:
| P | 1 | c | 9 | 9 |
|---|---|---|---|---|
| Powertrain Code | Fuel And Air Metering | Fuel Pump Module Control Circuit Range/Performance | Crankshaft Position Sensor A Circuit Malfunction | Reverse Input Circuit |
How to Fix Caterham Vx P1C99
Diagnostic Steps:
Oxygen sensors measure exhaust gas oxygen content to optimise air-fuel ratio. This optimisation improves fuel economy and reduces emissions. Sensors degrade over time and require periodic replacement.
Repair Solution:
Verify all electrical connections are clean and tight. Check for damaged wiring, especially in high-heat or high-vibration areas. Use manufacturer wiring diagrams for accurate diagnosis.
Technical Notes:
P1C99 on electronically controlled automatic transmissions relates to shift solenoid operation. The solenoid actuates hydraulic circuits controlling clutches or bands for gear changes.
Caterham Vx P1C99 Repair Cost
PCV system overhaul on the Caterham Vx — which resolves oil-mist contamination of the MAF sensor — costs $100–$200. The MAF sensor should be cleaned ($15–$25 DIY) or replaced ($80–$150) at the same time to ensure accurate fuelling after the fix.
P1C99 Description
P1C99 engine trouble code is related to Reverse Input Circuit.
Main Cause
The primary reason for P1C99 OBD-II Engine Trouble Code is: Fuel Pump Module Control Circuit Range/Performance.
Common P1C99 Misdiagnosis on the Caterham Vx
A frequent misdiagnosis on the Caterham Vx is replacing the oxygen sensor when P1C99 appears, only for the code to return within days. The actual cause is usually an exhaust manifold gasket leak introducing false air before the upstream O2 sensor — a much cheaper fix.
DIY Repair Guide: P1C99 on Caterham Vx
The coolant temperature sensor on the Caterham Vx is a straightforward DIY item (difficulty 2/5). Have a drain tray ready for the small amount of coolant that spills when the sensor is removed. Top up the cooling system afterwards and check for air pockets.
Preventing P1C99 on the Caterham Vx
Verify that the Caterham Vx engine air box lid clips are fully seated after any air filter service. An unsealed air box is a direct path for unmetered air past the MAF sensor and is an extremely common — and extremely embarrassing — cause of P1C99.
Frequently Asked Questions — Caterham Vx P1C99
A: Temporarily clearing P1C99 can help determine whether it is intermittent or persistent, but it does not fix the underlying fault. The code will return if the problem is still present. Do not clear codes just before an emissions test without a proper drive cycle.