P0700 – Transmission Control System Malfunction

Important:

P0700 does NOT tell you what is wrong with the transmission.

The real problem is stored as a separate transmission-specific code.

P0700 is a “flag” telling the engine computer that something is wrong in the transmission system.

Catalytic converters contain precious metals like platinum, palladium, and rhodium.

When damaged, replacement can cost:

💰 $800–1500 (aftermarket)
💰 $1500–4000+ (OEM)
💰 $3000–6000 on luxury vehicles

And many failures are caused by ignoring certain engine codes.

Here are the 5 most dangerous ones.

If your engine stalls while driving, it is not just inconvenient — it can be dangerous.

Modern vehicles rarely stall without a reason.
Often, a stored OBD2 code can explain exactly why it happened.

Here are the most common codes linked to engine stalling.

If your Check Engine Light is flashing, stop driving immediately.

A flashing light usually indicates active misfire that can damage the catalytic converter.

The list below applies to solid check engine lights only, where the car runs normally.

P0335 – Crankshaft Position Sensor “A” Circuit Malfunction

This code means the engine control module (ECM) is not receiving a proper signal from the crankshaft position sensor (CKP).

The crankshaft sensor is one of the most important sensors in the engine.

P0456 – EVAP System Very Small Leak Detected

This code means the vehicle’s evaporative emission control system (EVAP) has detected a very small leak.

The EVAP system prevents fuel vapors from escaping into the atmosphere.

A “very small leak” can be as small as 0.020 inches — almost invisible.

P0340 – Camshaft Position Sensor Circuit Malfunction

This code means the engine control module (ECM) is not receiving a proper signal from the camshaft position sensor (CMP).

P0128 – Coolant Temperature Below Thermostat Regulating Temperature

This code means the engine is not warming up as quickly as it should.

The engine control module (ECM) expects the coolant temperature to reach a certain level within a specific time.

If it stays too cool for too long → P0128 is triggered.

P0087 – Fuel Rail/System Pressure Too Low

This code means the engine control module (ECM) has detected that fuel pressure in the rail is below the required threshold.

P0430 – Catalyst System Efficiency Below Threshold (Bank 2)

This code means the catalytic converter on Bank 2 is not cleaning exhaust gases efficiently enough.