Signal Too Low. Permanent Fault

Other Diagnostic Trouble Codes
- Read off other diagnostic trouble codes (DTCs).
- Are EFI-541 and EFI-447 stored?

Yes:
^ Proceed to: Checking Fuse 3 section below.

No:
^ Proceed to: Checking Power Cable section below.





Checking Fuse 3
- Ignition OFF.
- Check that fuse 3 (11 B/3) is intact.

If reading is OK:
^ Proceed to: Checking Voltage To Fuse 3 section below.

If reading is incorrect:
^ Check circuit after fuse 3 for a short-circuit to ground.
^ For further information about the circuit after the fuse, see Wiring Diagram.
^ Proceed to: Verification section below.





Checking Voltage To Fuse 3
- Ignition ON.
- Fuse 3 (11 B/3) removed.
- Connect a voltmeter between the rear output on the fuse holder for fuse 3 (11 B/3) and ground.
- The voltmeter should read battery voltage.

If reading is OK:
^ Check cable between fuse 3 and pulsed secondary air injection system (PAIR) pump relay (2/53) terminal 2 for an open-circuit.
^ Proceed to: Verification section below.

If reading is incorrect:
^ Check cable between fuse 3 and main relay (2/32) terminal 3 for an open-circuit.
^ Proceed to: Verification section below.





Checking Power Cable
- Ignition OFF.
- Disconnect pulsed secondary air injection system pump relay A from relay base.
- Ignition ON.
- Connect a voltmeter between relay base terminal 2 and ground.
- The voltmeter should read battery voltage.

If reading is OK:
^ Proceed to: Checking Signal Cable Resistance section below.

If reading is incorrect:
^ Check cable between pulsed secondary air injection system pump relay (2/53) terminal 2 and fuse 3 (11 B/3), battery and pulsed secondary air injection system pump relay terminal A1 for an open-circuit.
^ Proceed to: Verification section below.





Checking Signal Cable Resistance
- Ignition OFF.
- Pulsed secondary air injection system pump relay disconnected.
- Connect an ohmmeter between relay base terminal 4 and ground.
- The ohmmeter should read infinite resistance.

If reading is OK:
^ Proceed to: Checking The Signal Cable section below.

If reading is incorrect:
^ Check signal cable between pulsed secondary air injection system pump relay terminal 4 and engine control module (ECM) # B38 for a short-circuit to ground.
^ Proceed to: Verification section below.





Checking The Signal Cable
- Ignition OFF.
- Pulsed secondary air injection system pump relay disconnected.
- Connect the breakout box and check ground terminals.
- Connect an ohmmeter between terminal # B38 on the breakout box and relay base terminal 4.
- The ohmmeter should read approx. 0 ohms.

If reading is OK:
^ Proceed to: Checking Pulsed Secondary Air Injection System Pump Relay section below.

If reading is incorrect:
^ Check signal cable between pulsed secondary air injection system pump relay terminal 4 and engine control module # B38 for an open-circuit.
^ Proceed to: Verification section below.





Checking Pulsed Secondary Air Injection System Pump Relay
- Reinstall engine control module and pulsed secondary air injection system pump relay.
- Ignition ON.
- Activate pulsed secondary air injection system pump.
- Start pulsed secondary air injection system pump.
- Does the pulsed secondary air injection system pump start?

Yes:
^ The cause of the diagnostic trouble code has been loose connections in the relay connectors.
^ Check connectors for contact resistance and oxidation and remedy.
^ Proceed to: Verification section below.

No:
^ Try a new pulsed secondary air injection system pump relay.
^ Proceed to: Verification section below.





Verification
After carrying out the repair, check that the fault has been remedied as follows:

- Reconnect connectors and reinstall components.
- Ignition ON.
- Activate pulsed secondary air injection system pump.
- A "clicking sound" should be heard from the relay and the pulsed secondary air injection system pump should start.

If reading is OK:
^ Fault corrected.

If reading is incorrect:
^ Proceed to: Fault-tracing Information section below.

Fault-tracing Information
The verification result shows that the fault persists.

- Do you want to exit fault-tracing?

Yes:
^ Fault not corrected.

No:
^ Proceed to: Other Diagnostic Trouble Codes section above.