DTC EFI-448

4-4-8 PULSED SECONDARY AIR INJECTION SYSTEM PUMP, FLOW FAULT





Trouble Code Conditions
- The pulsed secondary air injection system (PAIR) pump is checked by disabling the long-term fuel trim and stopping canister purge (CP) valve control. The pulsed secondary air injection system pump is started and the pulsed secondary air injection system valve is opened, if the short-term fuel trim integrator does not rise above a set value within 6 seconds diagnostic trouble code (DTC) EFI-448 Pulsed secondary air injection system pump, flow fault is stored.

Substitute value(s)
- Fuel trim disabled.

Possible source(s)
Flow too high:
- This diagnostic trouble code is always posted together with EFI-442 Pulsed secondary air injection system, flow too high and EFI-446 Pulsed secondary air injection system valve, leakage.

Flow too low:
- Defective pulsed secondary air injection system valve.
- Defective pulsed secondary air injection system pump relay.
- Defective pulsed secondary air injection system pump.
- Defective pulsed secondary air injection system solenoid valve.
- Vacuum hoses or check valve blocked.
- Pulsed secondary air injection system air hoses/pipes blocked.
- Open-circuit in pulsed secondary air injection system pump power cable or ground lead.

Fault symptom(s)
- None.