05 Prand Prix code P0410

[driveitforever]

My 05 Grand Prix shows error code P0410. Both the secondary air pump and relay are good. According to my code scanner the circuit is not being turned on in open loop as it should be. I believe that the next step back is the PCM. Can anyone verify that. Does anyone have a good wiring diagram for that circuit

[BNaylor]

Welcome to AF.

It would help to post your mileage and which model '05 GP or engine size.

[driveitforever]

The car is a bottom end grand prix with series II 3.8

[BNaylor]

As far as a good wiring diagram the GM FSM from Helm, Inc.

The DTC is generated because the air pump is not flowing the correct amount of air into the exhaust system. The test is always done in open loop mode before sufficient or proper engine warmup and switching over to closed loop mode when other conditions are right. The sensor being used to sample and determine if there is a fault is the pre-CAT 02 sensor. The 02 sensor voltage is forced to go below 152 mV by the air pump for a lean ratio time period of at least 3 seconds. The two tests run are intrusive and non-intrusive. Do you have a full function scanner capable of checking the 02 sensor switching?

Also, what is your mileage?

[driveitforever]

Originally Posted by BNaylor

As far as a good wiring diagram the GM FSM from Helm, Inc.

The DTC is generated because the air pump is not flowing the correct amount of air into the exhaust system. The test is always done in open loop mode before sufficient or proper engine warmup and switching over to closed loop mode when other conditions are right. The sensor being used to sample and determine if there is a fault is the pre-CAT 02 sensor. The 02 sensor voltage is forced to go below 152 mV by the air pump for a lean ratio time period of at least 3 seconds. The two tests run are intrusive and non-intrusive. Do you have a full function scanner capable of checking the 02 sensor switching?

Also, what is your mileage?

My scanner shows the o2 sensor flipping back and forth from approximately .1 to .8. When monitored from cold start the scanner shows open loop and the secondary air system is not activated. Open loop does not stay on very long. The car has 64000mi. on it.

[tblake]

That O2 sensor reading sounds like its from the pre-cat or sensor. I think Bob was wondering what the post cat O2 sensor is doing (the one used to monitor cat efficiency) during open loop.

[BNaylor]

Actually the front 02 sensor. The rear post CAT 02 sensor is not used for secondary air pump emissions testing by the PCM module, however, the rear 02 sensor is probably used to get the results of the tests but the PCM looks at the output of the front 02 sensor signal as I mentioned above. Testing on air injection is only done in open loop mode. But according to the OP the air pump is not even turning on. During air pump testing the pump will turn on and you should hear it. Regardless, troubleshooting these circuits can be a PITA.

With only 64K miles double check your warranty info and see if the emissions fault is covered by the emissions warranty and you don't have to live in California since it is a LEV2 certified engine and will be found in other green states such as New York. Best to let the GM dealer service department take care of the issue if it is covered.

[tblake]

Sorry Bob! My mistake