Code 45
Code 45 is a diagnostic trouble code related to a rich exhaust indication on the Pontiac Fiero.
Code 45 indicates that the ECM is seeing an oxygen sensor signal that suggests the engine is running rich.
Overview
The Oxygen sensor monitors oxygen content in the exhaust. The ECM uses this signal to adjust fuel mixture during closed-loop operation.
Code 45 is set when the ECM detects a rich exhaust condition for longer than expected. A rich indication can be caused by too much fuel, too little air, excessive fuel pressure, leaking injectors, a sensor problem, or an electrical issue.
Flash pattern
Code 45 is displayed as:
- Four flashes
- Pause
- Five flashes
This represents code 45.
Animated flash pattern:
Meaning
Code 45 usually indicates that the ECM sees the exhaust mixture as too rich.
Possible causes include:
- Faulty oxygen sensor
- Oxygen sensor wiring problem
- Excessive fuel pressure
- Leaking fuel injector
- Faulty fuel pressure regulator
- Restricted air intake
- Dirty air filter
- MAP sensor problem
- Coolant temperature sensor problem
- Manifold air temperature sensor problem
- Poor ground or connector problem
- ECM input problem
Symptoms
Possible symptoms may include:
- Check engine light
- Poor fuel economy
- Black exhaust smoke
- Fuel smell
- Rough idle
- Fouled spark plugs
- Hesitation
- Poor acceleration
- Failed emissions test
- Little or no obvious drivability problem
Diagnosis
Basic diagnostic checks include:
- Confirm that Code 45 is present.
- Inspect the oxygen sensor wiring and connector.
- Check for other stored trouble codes.
- Check fuel pressure.
- Inspect the fuel pressure regulator.
- Check for leaking injectors.
- Inspect the air intake and air filter.
- Check MAP sensor vacuum and wiring.
- Check coolant temperature sensor readings if possible.
- Check manifold air temperature sensor readings if possible.
- Check grounds and ECM connections.
Fuel pressure and injectors
Excessive fuel pressure, a leaking injector, or a faulty fuel pressure regulator can cause a rich condition.
Related topics:
Sensors
Incorrect sensor information can cause the ECM to command too much fuel.
Related topics:
- Oxygen sensor
- Coolant temperature sensor
- Manifold air temperature sensor
- MAP sensor
- Code 13
- Code 14
- Code 15
- Code 23
- Code 25
- Code 33
- Code 34
Related codes
Related fuel-control and oxygen-sensor codes include:
Notes
Code 45 should not automatically be treated as a failed oxygen sensor. Fuel pressure problems, leaking injectors, sensor faults, wiring faults, and ECM input problems can all cause a rich indication.
Diagnosis should determine whether the engine is actually running rich or whether the ECM is receiving a misleading signal.