C100A Diagnostic Trouble Code

C100A is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a C100A diagnostic trouble code may include:

Rich or lean exhaust
Fuel pressure too low
Engine surge
Poor acceleration

Possible Causes :

Faulty IMRC actuator relay (if equipped)
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Repair Processes :

If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector.

Process Tips

Diagnostic trouble code C100A is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before C100A.

Fortunately, C100A is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C100A Trouble Code For Specific Cars

C100A Velorex 16 PSP Switch Out of Self Test Range
C100A Lotus Exige S3 Traction Control Motor Potentiometer Circuit Failure
C100A Om Tipo Damper LR Circuit Short to Ground
C100A Venturi Atlantique Pump Speed Signal Fault
C100A Rambler Classic Fuel Temperature Sensor U Circuit Low Input
C100A Mercedes Cls 63 ABS Outlet Valve Coil RR Circuit Short To Battery
C100A Daimler De Headlamp Mode Select Circuit Failure