List of trouble codes that all showed up at once

[Malibu369258]

Well haven't posted on here in ages, but finally have something to post/ask about. My girlfriend picked up a '99 Alero (3400 V6) about a month ago and a list of trouble codes popped up all at once.

Was wondering if there is a connection as to why all of this showed up at once... Car never had any codes before that.

The codes are as follows

C1223 Left Rear Wheel Speed Sensor Input Signal is 0

C1224 Right Rear Wheel Speed Sensor Input Signal is 0

C1225 Left Front Excessive Wheel Speed Variation

C1242 Pump Motor Circuit Open

C1286 Steering Sensor Bias Malfunction

P0101 Mass or Volume Air Flow Circuit Range/Performance Problem

[AleroB888]

Originally Posted by Malibu369258

Well haven't posted on here in ages, but finally have something to post/ask about. My girlfriend picked up a '99 Alero (3400 V6) about a month ago and a list of trouble codes popped up all at once.

Was wondering if there is a connection as to why all of this showed up at once... Car never had any codes before that.

The codes are as follows

C1223 Left Rear Wheel Speed Sensor Input Signal is 0

C1224 Right Rear Wheel Speed Sensor Input Signal is 0

C1225 Left Front Excessive Wheel Speed Variation

C1242 Pump Motor Circuit Open

C1286 Steering Sensor Bias Malfunction

P0101 Mass or Volume Air Flow Circuit Range/Performance Problem

The P0101 would be worth investigating, hard to say with some of these codes, though. I've switched PCMs and programs many times and it seems some codes appear for no good reason. Changes were also made by GM to the programming for earlier models to correct drivability issues.

Here are some codes I get right now in my '99 that I can't account for:

[guiguilandry]

look if there is corrosion in the EBCM connector...

[Malibu369258]

Well cleaned the MAF and put in a new air filter. Really needed it.

And bam the codes are all gone...

[guiguilandry]

good for the last.... but for the first 5 codes it has nothing to do with them... and they were code that doesn't trigger the check engine light...