trouble code question

[darkz711]

I was using free scan to see if the new flash for my ECU worked and I got 3 error messages, one for the carbon canister pressure, one for my electrical fan not working and one for EAS. What does EAS stand for? Its a 1995 camaro z28. I just got the EGR turned off by the new flash and having one bad o2 sensor that i still need to replace. Is that EAS the o2 sensor not working? I was just wondering what it meant.

oh and i had the car running for about 90 seconds and i had 25000 knocks, is that a lot of knocks or is that normal, 25000 is a big number

[Formulaboy95]

What is the DTC# for the EAS.

Is that what the knock count started at, or does it continually climb? Spark knock retard degrees - If you shut the car off without disconnecting from the software first, the # jumps to a high or random # at the end.

[darkz711]

What is the DTC# for the EAS.

Is that what the knock count started at, or does it continually climb? Spark knock retard degrees - If you shut the car off without disconnecting from the software first, the # jumps to a high or random # at the end.

its code 27, and turning the car off before disconnecting just dropped the knock from 25000 to 42

[Formulaboy95]

27 is EGR vacuum control solenoid circuit.

I think you are supposed to disconnect from the program first and then shut the car down, that is what makes the knock count jump at the last second.
As long as you are not seeing any knock spark retard, or the knock count going up while driving, you should be fine.

[darkz711]

EGR?? But i just got that programmed out by MadZ28, what gives

[Craig 94 TA GT]

Hmmm...DTC 27 only occurs when the PCM detects the wrong voltage potential on circuit 435 for 26 seconds. The PCM controls the valve by providing the ground through ct 435. So I'm thinking that it's not programmed out??

[Craig 94 TA GT]

I just did more research on "EAS", and are you sure it's DTC 27? I found this:
http://web.camaross.com/forums/showt...hlight=eas+dtc

According to that, EAS is DTC 29, secondary air injection pump circuit. This is when the PCM detects the wrong voltage potential for 26 seconds on CKT 436, which is where the PCM provides the ground path to the air pump relay coil.

[Formulaboy95]

It would seem like it was not removed... I would email them to check.
Are you using a fan switch also? that triggers the fan code

DTC 29 is Air Pump.
Mine was toast, and one of the recalled TSB Units. Might want to run the vin to check to see if that is one of the units that need replacing too. I lost the link to the site though.

[darkz711]

It would seem like it was not removed... I would email them to check.
Are you using a fan switch also? that triggers the fan code

DTC 29 is Air Pump.
Mine was toast, and one of the recalled TSB Units. Might want to run the vin to check to see if that is one of the units that need replacing too. I lost the link to the site though.

Ya the air pump was a recall apparently, i was tlaking to the parts guy today. I have a fan switch, but regardless my fans don't work, with the switch on or off. I didn't put the phone switch in so i have to find a wiring schematic to see where they are disconnected.

what is the carbon canister pressure problem?

[Injuneer]

You really need to just post the code numbers, and let us take it from there. If you want to look the codes up, rather than using a "generic" code list, use the one on Shoebox's Tech Pages... it is LT1 specific.

http://shbox.com/1/Dtcs.htm

EAS is most likely DTC 29 for the AIR pump. You can delete the pump, disconnect the harness connector, and as long as there is a good fuse on the power supply circuit to the relay, you will not get a DTC code.

The only EEC canister code on OBD-I is not for canister pressure. Its for the EEC purge solenoid (DTC 26). Means either the EEC purge solenoid is missing, burned out, the fuse is blown, or the wiring is faulty.

Which fan code did you get, there are several. If you have a fan switch, and it isn't wired correctly, it will set the DTC's for the fans. Again, Shoebox has the workaround on his Tech Pages.

The knock count is a field that is "cumulative".... its showing you the total knock count since last time the PCM was reset, or when it reached the limit of the binary field size and cycled to "0". The absolute number in the scan isn't important.... its whether the number is changing over time. It isn't unusual for it to increase a bit on startup, but otherwise it should hold fairly steady. It can invoke a burst knock response if it starts to increase.

[Rob B (shoebox)]

From my observations, the knock counts always increments up when you start the car and when you shut it off. Normal stuff, there. Fred also explained how the counter "rolls over".

[darkz711]

no i got DTC 26, DTC 27, those are more two codes and then the fan switch
fan 1 electrical error

[Injuneer]

DTC 26 = Evaporative Emission (EVAP) canister purge solenoid valve circuit

I already explained DTC 26. Just curious.... did you delete the EEC system?

DTC 27 = Exhaust Gas Recirculation (EGR) vacuum control signal solenoid valve circuit

Same possible problems as the EEC solenoid - solenoid is not connected, solenoid is burned out, fuse for power supply is blown (same one that supplies the EEC solenoid), or the wiring is screwed up/burned.

Again, when you had the EGR turned off, did you delete the solenoid? While they may have turned off the diagnostic for "EGR circulation" (DTC 32), they may have assume you would leave the solenoid in place. There are two separate diagnostic routines.

DTC 77 = Cooling fan relay control circuit

Is that the fan code?

Somehow this seems a lot more difficult than it has to be.

[darkz711]

its one of the options from MadZ28 to delete the EGR not turn of the diagnostic. So maybe the program wasn't currect, i emailed him back already to see whats up. The EEC was not programmed out. And the fan code, is Code 77.

as far as the EGR, there is no vacuum being formed. N20LT4bird and i were checking it out back in october, so thats the problem with the EGR i just thought it was programmed off but apparently it's still there

[Injuneer]

I'll try and explain this one more time, and then I'll leave you alone. DTC 27 has NOTHING to do with EGR flow, vacuum for the system, whatever. It is generated by a PCM check on the condition of the solenoid energizing circuit. Plain and simple.