Faulty Signal

Checking Other Diagnostic Trouble Codes
- Read off other diagnostic trouble codes (DTCs).
- Is diagnostic trouble code EFI-445 stored?

Yes:
^ To continue Fault-tracing see; Code EFI-445 Pulsed Secondary Air Injection System Pump Signal.

No:
^ Proceed to test step below.





Checking The A/C Relay Signal Cable
- Connect the test box and check ground terminals.
- Connect engine control module (ECM).
- A/C button on.
- Blower fan at low-speed.
- Start the engine and idle it.
- Connect a voltmeter between connectors # 40 (# B40) and # 28 (# B28) on the test box.
- The voltmeter should read 0 - 2 Volts.

If reading is OK:
^ To continue Fault-tracing see; Faulty signal. Intermittent fault.

If reading is incorrect:
^ Proceed to test step below.





Checking The A/C Relay
- Ignition off.
- Disconnect the A/C relay (2/22).
- A/C switch on.
- Blower fan at low-speed.
- Start the engine and idle it.
- Connect a voltmeter between connectors # 40 (# B40) and # 28 (# B28) on the test box.
- The voltmeter should read 0 - 2 Volts.

If reading is OK:
^ Try a new A/C relay.

If reading is incorrect:
^ Check cable between A/C relay terminal 4 and engine control module (ECM) # B40 for a short-circuit to supply voltage.

Fault-tracing Information
- Fault-tracing for this diagnostic test is not followed by a verification.
- Do you want to repeat the fault-tracing for this diagnostic test?

Yes:
^ Return to Checking Other Diagnostic Trouble Codes section above.

No:
^ Fault corrected