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2005 Chrysler Sebring air injection pump draining battery

Hey guys,
A couple of weeks ago, with the car turned off, keys out of the ignition - about every thirteen seconds you could hear the air injection pump coming on, running for a couple of seconds and then turning off. The next day the car battery was dead (no surprise) so we charged it up and took it to the shop (AAA) . They told us that it was a faulty MAP sensor and didn’t give us a price quote to fix it, just an invoice/diagnostic bill. But they did unplug the air injection pump so that the battery wouldn’t keep getting drained. We drove the car home and called them the next day to get an estimate for the repair and they said that they misdiagnosed the problem and that it was actually a MAF sensor that was causing the air injection pump to come on when the car was turned off and that it would cost around 500 dollars for the part and labor. Too steep so we decided to hold off on the repair. Understanding our reluctance to go through with the repair, they recommended that we plug the air injection pump back in and still drive the car but to make sure that we unhook the battery at night/when the car would be sitting for many hours without being started.

Here’s where it gets a little confusing (or at least for me). I did take AAA’s advice and went ahead and plugged the air injection pump back in and for the last couple of weeks it’s been fine. No issues with the battery being drained whatsoever/no air injection pump coming on with the car turned off. But today the air injection pump started doing its thing again.
The check engine light was on so I hooked my code reader up and pulled the following codes:

PO128 (thermostat coolant temp below regulating temp)
PO491 (secondary air injection system (Bank 1)
PO2431 (secondary air intake system FLW/Perf B1

So what do you guys think? Does all this point to a faulty MAF sensor?

The diagnosis doesn’t make sense to me but I don’t have any data about the circuit. It seems to me that power to the pump should normally be cut off with the ignition power. I would look for trouble with whatever supplies it power. That isn’t going to come from a sensor.

Yeah. Exactly what I was thinking too. If the power is off, and the engine isn’t running then there should be no reason or even a need for power to be going to the pump. Doesn’t make sense.
I’ll do what you suggested and try to get to the bottom of what’s supplying power to the pump.

Normally when an air injection pump stays on the relay is stuck. Electric air injection pumps draw a lot of current and the relays wear out.

I would think the last two codes came from having the air injector unplugged. I would clear the codes and see if the P0128 comes back. As far as the electrical drain I would look at the relay or whatever controls the air injection pump.

Are you sure you mean air injector pump?

The reason I ask is, neither my on-line repair reference site shows an air injection pump for the 2.4, 2.7, or 3.0 liter engines, nor does RockAuto list an air injection pump for these engines.


I’ll check. Give me a minute

I guess this is it:

Yeah, ‘‘air injection pump’’ is what the invoice from AAA has it down as in one sentence then in another sentence it says; ‘‘Correction: faulty MAP sensor to secondary air pump causing it to cycle on and draw power when the engine is not running.’’

And I just found at the top of the invoice that the engine is a 4-148 2.4L DOHC if that makes a difference.

Wow! $11.75 sounds a lot better than $500. Hopefully it is just a bad relay.

Thanks for the link insightful

I think you have a leak in the auto leveling suspension system of the car, your codes are indicative of other issues. Can you pull the air pump leveling fuse and see if the trouble goes away?

LOL. Very funny. Reminds me of the time my brother was telling me about people taking their cars to the repair shop and being told by the mechanics that their car had bad muffler bearings. Hahaha… classic stuff : )

I also think you need to start with the air pump relay

As for P0128 . . . either your thermostat is stuck open, or the coolant level is low enough to generate that code

Check the coolant level

If it’s fine, replace the thermostat

I have the air injection pump removed from the car. There’s no relay mounted to it. Does anyone know where the relay is located? Every google search I did pointed to the relay being bolted to the side of the injection pump.

Look for an electric panel with a cover by the inner fender…usually on the drivers side.
It should say Relays/fuses.

I’ve already found it but there’s no labeling on the underside of the black cover telling you what’s what. I guess I should probably find a repair manual for this car.

I suggest you purchase a factory service manual for the wiring at least. Ebay is a good place to find them at good prices. The factory manuals give you all the details that other manuals don’t have, like where things are located.

Some data I am looking at shows there is a relay for the 2.4L PZEV model tied to fuse 7 (40A) in the power distribution center under the hood. The relay is not located in there though. The data shows a Lt blue/wht wire from the panel ties into a blk wire that goes to the relay.

Thanks for looking that up Cougar. I’ll try and follow that wire…

I can’t find anywhere under the hood where it says whether or not this car is a PZEV model.
Maybe a silly question, but is it stamped on the engine somewhere?

I won’t have access to the info for 2005 until tomorrow. This is the air injection pump diagram for the 2004 Sebring sedan;

It’s a 2005 Sebring sedan 2.4L DOHC.

And I found out from the owner’s manual that it is in fact a PZEV model. Stands for Partial Zero Emissions Vehicle.

I have a relay out - not sure if it’s the right one. It has wires running into the plug that plugs into it from two different sets of wires. A few of the wires going into it are from the air injection pump (good sign) and I’m not sure where the other wires were coming from but it (the relay) definitely ties in with the air pump somehow. Anyone know what type of readings I should be getting if the relay is in good working order? I tested it with my multimeter and it gave a reading of 73.2 ohms when I touch prongs 85 & 86. In case it helps, there’s three more prongs on the relay labeled 87, 87a, and 30. And on the bottom of the relay casing it has the numbers 56007078