P1680

SECONDARY AIR INJECTION RELAY OR A/C RELAY





Fault Symptom.
CHECK ENGINE lamp (MIL) on.

Conditions.
One of the control module's integrated circuit output stages is used for checking the secondary air injection relay and A/C relay.

Should a fault, open circuit or short circuit to ground or battery positive (B+) occur, diagnostic trouble code P1680 will be generated.

Diagnostic Help.
^ The relay for controlling secondary air injection can be activated with the ISAT scan tool.
- Select "ACTIVATE".
- Select "SECOND. AIR RELAY".
The relay (and secondary air injection) is activated at a frequency of 0.5 Hz for 30 seconds.
^ The relay for controlling the A/C can be activated with the ISAT scan tool.
- Select "ACTIVATE".
- Select "AC RELAY".
The relay (and the compressor) is activated at a frequency of 0.5 Hz for 30 seconds.

Check The Wiring.
Intermittent faults may occur as a result of temporary short circuits and breaks in the wiring. Jiggle the wiring at several points and in different directions to ascertain whether the wiring harness, including any connectors, is causing the trouble. Observe the multimeter, ISAT scan tool or test lamp while doing this.





Diagnostic Procedure.
1 Check the resistance of the secondary air injection relay

- Remove the secondary air injection relay (Relay 584 is located in the main fuse box In the engine bay.)
- Check the resistance of the relay, taking a mading (in ohms) across:
^ pins 85 and 86: about 85 ohms.

Is the resistance reading OK?

YES:
^ Continue with point 2
NO:
^ Change the relay. Continue with point 7.





2 Check the secondary air injection relay's power supply

- Connect the test lamp to:
^ pin 86 of the relay socket and a good grounding point.
- Turn the ignition switch to the ON position.
The test lamp should light up.

Did the test lamp light up?

YES:
^ Continue with point 3.
NO:
^ Check and if necessary repair or replace the wiring, including connectors, between pin 86 of the relay socket and the power supply (+15 circuit). Continue with point 7.





3 Check the secondary air injection relay's ground connection

The relay is connected to ground via pin 19 of the control module.

- Connect the test lamp to the relay socket between:
^ pins 85 and 86.
- Connect an ISAT scan tool.
- Turn the ignition switch to the ON position.
- Select "ACTIVATE".
- Select "SECOND. AIR RELAY".
The test lamp should flash.

Test lamp flashing?

YES:
^ Continue with point 4.
NO:
^ The test lamp does not light up at all or is on continuously. Check and if necessary repair or replace the wiring between pin 10 of the control module and pin 85 of the relay socket. Continue with point 7.





4 Check the resistance of the A/C relay

- Unplug the A/C relay (located in the main fuse box in the engine bay).
- Check the resistance of the relay, taking a reading (in ohms) across:
^ pins 85 and 86 about 85 ohms.

Is the resistance reading OK?

YES:
^ Continue with point 5.
NO:
^ Change the relay. Continue with point 7.

5 Check the A/C relay's power supply

- Connect the test lamp to:
^ pin 86 of The relay socket and a good grounding point.
- Turn the ignition switch to the ON position.
The test lamp should light up.

Did the test lamp light up?

YES:
^ Continue with point 6.
NO:
^ Check and if necessary repair or replace the wiring, including connectors, between pin 86 of the relay socket and the power supply (+15 circuit). Continue with point 7.





6 Check the A/C relay's ground connection

The relay is connected to ground via pin 48 of the control module.

- Connect the test lamp to the relay socket between:
^ pins 85 and 86.
- Connect an ISAT scan tool.
- Turn the ignition switch to the ON position.
- Select "ACTIVATE".
- Select "AC RELAY".
The test lamp should flash.

Test lamp flashing?

YES:
^ Continue with point 7.
NO:
^ The test lamp does not light up at all or is on continuously. Check and if necessary repair or replace the wiring between pin 48 of the control module and pin 85 of the relay socket. Continue with point 7.

7 Final check

- Clear the diagnostic trouble code.
- Implementation of driving cycle:
^ Drive the car at varying engine loads and rpm for 5 minutes.
- Evaluation of driving cycle:
^ Check whether the diagnostic trouble code has recurred.

Has the diagnostic trouble code recurred?

YES:
^ Continue at "Before Replacing a Control Module". Component Tests and General Diagnostics
NO:
^ The steps taken to rectify the fault were correct.