2000 Pontiac Grand Prix check engine light on P0410 DTC

[aaronab1]

Reads code P0410 secondary air injection system. Where can I find circuit relay? How can I test air pump to see if it is working properly?

[BNaylor]

Welcome to AF.

Which engine do you have? Secondary air injection problems can be complex to diagnose and troubleshoot.

Basically you have an air injection system malfunction meaning diagnostics has detected an air pump that is not flowing the proper amount of air into the exhaust system. Although the pump could be flaky it does not mean the air pump itself is bad. Also, there is a check valve and air pump solenoid. Technically, the PCM module controls the circuits and all testing.

Two tests are run by the PCM. Non-intrusive and Intrusive.

The non-intrusive test is run at startup in open loop mode. It looks for 02 sensor voltage above 598.96 millivolts for a rich time ratio of 1 but is failing. To pass the 02 sensor voltage must be below 0 mvolts for a lean tme ratio of 1. Therefore, to fail the 02 sensor voltage is below 598.96 mvolts for a minimum of 5 seconds after the pump is turned off. Must have above 598 mvolts for 25 samples to pass.

In the intrusive test the air pump is turned on to force a change in the 02 sensor signal. The 02 sensor signal must be forced continuously below 73.785 mvolts for greater than 1.5 seconds to pass.

Also, GM has a TSB out covering a mod where a plastic shield is added because the air pump was accumulating water due to it's poor location.

[aaronab1]

hi i have a 3.8 liter. thanks for the reply i have been hearing about that bad location of the air pump. i called the dealer they talled me that is a common problem. also i have 110.000 miles i will be taking the pump out this week to take a look at it i hope thats the problem because i need a sticker.i appreciate the reply thanks.