Secondary Air System
FAULT DIAGNOSIS, SECONDARY AIR INJECTION SYSTEM
Fault Symptom.
Emission control affected.
NOTE: Diagnostic trouble codes P1206 and P1207 will be generated when the control module output (pin 26) is open or shorted to ground/batt+. The trouble code is generated by electrical faults. Fault diagnosis in this section deals with other faults.
Diagnostic Procedure.
1. Check MAXI-fuse 1 (air injection pump) and fuse 13 (solenoid valve). Both fuses are located in the front main fuse box.
2. Check the operation of the secondary air injection system for the rear bank of cylinders.
Connect the Scan Tool.
Remove the secondary air injection relay.
Start the engine.
Select "READ FUNCTIONS".
Select "REAR OXYGEN SENSOR". When Lambda control does not work, i.e. the Scan Tool display oscillates between 0.1 V and 0.9 V, connect a jumper lead across pins 30 and 87 of the relay base for 5-10 seconds. The oxygen sensor voltage does not oscillate and remains steady at 0.45 V.
Repeat the same procedure for the front bank of cylinders.
Select "FRONT OXYGEN SENSOR".
If the results of these tests are not OK, proceed to step 7.
If the test results are OK, continue with step 3.
3. Check the operation of the secondary air injection relay and air pump.
Fit the secondary air injection relay.
Ignition switch in the ON position.
Select "ACTIVATE".
Select "SECOND. AIR RELAY". This command activates the relay at a frequency of 0.5 Hz for 30 seconds.
- Listen for the sound of the air pump and relay working.
If the pump and relay work, proceed to step 5.
If they do not, continue with step 4.
4. Check the electrical interfaces of the relay and air pump.
^ Ignition switch in the ON position.
Connect the test lamp to pin 30 of the relay base and a good ground.
- The test lamp should light up.
If it does not, continue fault diagnosis in the Electrical System.
^ Ignition switch in the OFF position. Checking the wiring harness for continuity.
Check:
- the lead between pin 87 of the relay base and pin 2 of the air injection pump.
- the lead between pin 1 of the air injection pump and grounding step G30 for continuity.
If the leads are OK and the air injection pump is live and connected to ground but still does not work, change the air injection pump.
5. Check the solenoid and vacuum valves.
Remove fuse 13.
Start the engine and run it at idling speed.
Force the solenoid valve to work by connecting battery positive to the output side of the fuse in the fuse holder.
- Listen to the pump's inlet line.
- Exhaust noise will be heard when the valve is open but nothing will be heard when it is closed.
If the valve is OK, check the lead between pin 87 of the relay base and the input side of the fuse in the fuse holder for continuity.
If the valve is not OK, continue with step 6.
6. Check the solenoid valve's electrical interfaces and the mechanical connections of both valves.
Remove the solenoid valve.
Connect the test lamp to pins 1 and 2 of the solenoid valve's female connector.
Select "ACTIVATE".
Select "SECOND. AIR RELAY".
- The test lamp should flash.
If the test lamp flashes:
- Check the resistance of the solenoid valve.
Nominal resistance is 40 ± 5 ohm at 20°C.
If the resistance is not OK, change the solenoid valve.
- Check the mechanical connections of the valves.
The solenoid valve opens ON/OFF when supplied with power.
The vacuum valve opens ON/OFF when vacuum is present.
When the vacuum valve is open an audible sound can be heard in the pump inlet.
If the test lamp does not flash, check:
^ the lead between pin 1 of the solenoid valve and grounding step G30.
^ the lead between pin 2 of the solenoid valve and pin 87 of the relay base for continuity/ shorting.
7. The secondary air injection circuit appears to be in proper working order.
Check that the control module activates the relay according to specification.
If the activity cycle is not OK, continue at "Procedure Before ECM Replacement". Component Tests
If the activity cycle is OK, drive the car on test and check whether the fault symptoms recur.