P0171, fuel trim lean bank 1, assuming no fresh air leaks after the MAF sensor, unmetered airflow causes P0171 as do other issues cause P0171.Jessica, Today I took the car to Auto Zone and they ran a code check. The car popped 17 codes!!! Two of them were multiple hits (3 each). The check engine light stays on, and for some reason, the electronic ignition will not work now. I will list the codes for anyone that has experience with them.
P0171 (3x's), PO107, PO113, PO122, PO223, PO300 (3x's), P1682, P2122, P2123, P2127, CO561, CO242.
When I lock the door and try to engage the electronic ignition, it just flashes the parking lights and doesn't start.
I unhooked the MAF sensor and the car runs near perfectly, but the check engine light remains on, and the auto ignition still doesn't work, and it gives the same messages, "ESC Service", etc.
P0107, MAP sensor short to ground. Not necessarily the MAP sensor, could be anything on the 5volt reference 1 circuit pulling the 5 volt line low. Can be the sensor itself or the signal circuit, not cut and dried.
P0113, Intake air temperature high. Bad MAF sensor connector? MAF and IAT are in the same sensor and I did my father's connector already for that problem. Just a thought.
P0122 throttle position sensor 1 low voltage. Loss of 5 volt reference?
P0223, TP sensor 2 high voltage. Loss of sensor ground?
P0300, misfire code. Would need to look at misfire data to see what cylinder is misfiring. Only would set specific cylinder code if there is only one cylinder misfiring. Once other cylinders show misfires, real or not, the ECM sets the P0300.
P1682, ignition switch code. Was somebody pulling fuses with the key on? Ignition switches, gen 6 and up are not the same as gen 5 ignition switches and their well documented issues. Gen 6 and up, the ignition switch is really just a BCM input telling the BCM what position the ignition is in. The BCM is the Power Mode Master and wakes up other modules when needed, radio for example is powered at all times but is sent a wake up signal from the BCM to turn it on.
P2122, Accelerator position sensor 1 low voltage
P2123, APP sensor 1 high voltage.
P2127, APP sensor 2 low voltage. Those three codes, again, pulling connectors off with the key on? Even pulling connectors off with the key off will set codes on these late model cars, the ECM is awake even with the key off for a period of time.
C0561 and C0242. informational codes. Telling you there is a problem elsewhere, kind of pointless since all you are told to do is look for codes in other modules. Kind of a NSS code.
Remote start will not function with the check engine light on, so fix the check engine light cause and see if remote start works then.
With MAF unplugged, the ECM runs in a backup mode and uses MAP sensor inputs along with throttle position to control fuel delivery, not great but the car doesn't let you sit stranded.
I would clear codes and see what resets and go there. I doubt you have all these issues unless you have a bad ECM ground or something. That would be one of the few things that would cause so many issues at once. MAF/IAT sensor connectors do go bad. The engine flexes and the wires just break internally sometimes. Replacing the pigtail is usually all you need in that case.
If you do have TP or APP issues, it gets more involved. TP and APP issues are there for a split second and gone, they are not normally hard faults, cycling the key will usually allow normal engine operation until the code resets. TP sensors are known for issues, TP sensor used to be serviced only as part of the throttle body but service kits are becoming available to replace just the sensor. Depends on application as to whether it is serviced separately or not by GM. Wiring can also be an issue and restringing the affected circuits is the only way to go. Circuits must be restrung terminal to terminal for an effective repair since all too often the issue is at the terminal either at the component or the module (ECM in this case). Disregard the messages for now and address the codes that reset after being cleared, the code and the messages you see are being caused by the same problem.
What you can try to help isolate a bad MAF/IAT connector is with the engine idling in PARK, slowly manipulate the harness close to the MAF/IAT sensor. If the engine stumbles and you can repeatedly duplicate it, you are onto something. If the ECM sees a MAF signal fluctuate irrationally, it will ignore it and set a code, then manipulating the harness will have no effect since the ECM is ignoring what it sees.