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Discussion Starter #1

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I'm not sure if it's just my browser or not, but I'm not able to see your images. Can you elaborate on your issues, what vehicle, etc?
 

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I'm not sure if it's just my browser or not, but I'm not able to see your images. Can you elaborate on your issues, what vehicle, etc?
I can see the thumbnails but they will not open.
 

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Tank,
My 2017 2.4L Equinox shows module $7E8 as the ECM. To me the first image looks like Evap troubles. ( Gas cap, an Evap vacuum leak, Evap solenoid valves not opening/closing properly ) Some of the remaining errors look like O2 sensor troubles but since there are two heater fails at the same time I would check the O2 heater circuits first before replacing the O2 sensors. The slow response message might be signs of cat failure or poor cat performance. I would try to resolve the O2 sensor issues and then retest, before replacing the cat.
 

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Discussion Starter #6
O2 sensor delayed response rich to lean
Mid 01
Tid 91
Min -32.768
Max 0.440
Value -0.018
Unit s
Failed

Evpd purge vac fail test
Mid 3d
Tid c5
Min -8192.0
Max 2500.0
Value 203.5
Unit pa
Failed

Heater resistor error test
Mid 42
Tid d3
Min -4.199
Max 2.481
Value 0.104
Unit (blank)
Failed
 

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Discussion Starter #7
5v reference 1, 3 and 4 are 5.01v
reference 2 is 5.03 v those values are in ref. Ignition 1 is 13.8v and I believe that is correct.

Random rough idle and stall in reverse. I replaced the evap solenoid yesterday, car immediately stalled, took it for a drive and was running very strong, responsive and smooth.
 

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Discussion Starter #8
Tank,
My 2017 2.4L Equinox shows module $7E8 as the ECM. To me the first image looks like Evap troubles. ( Gas cap, an Evap vacuum leak, Evap solenoid valves not opening/closing properly ) Some of the remaining errors look like O2 sensor troubles but since there are two heater fails at the same time I would check the O2 heater circuits first before replacing the O2 sensors. The slow response message might be signs of cat failure or poor cat performance. I would try to resolve the O2 sensor issues and then retest, before replacing the cat.
Last time I changed my oil I noticed a metal ring hanging before the flex pipe (towards the front of the car) I cut it off as it was just bouncing around. It was maybe 1/8" thick. I was told it was possibly part of the flex pipe.
Could I have a slight leak causing that?
The heater fails I'm not too familiar with, I know about that circuit and what it does, just not sure how to diagnose it. Could it be a fuse, bad ground or poor connection. Going back to the metal ring; maybe a ground connection is corroded? If I'm reading some of these correctly; there is a problem but values are close so no cel is thrown? Evap purge replacement seemed to help alot with some idle issues. poor cat/o2 should still affect that. Of course it's raining so crawling under my car is a no go for today lol
 

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How many miles on the O2 sensor ? I just changed my 100k sensors with a fresh set of AC ones in my Tahoe after loosing mpg for the last 20k miles and after 1500 miles my avg. mileage is up 1.9 mpg. on multiple identical 500 mile trips before the virus.
O2 sensors are now on my maint. replacement list at 80k miles on my fleet.
No codes or detectable issues with the old ones either.
 

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Discussion Starter #10
How many miles on the O2 sensor ? I just changed my 100k sensors with a fresh set of AC ones in my Tahoe after loosing mpg for the last 20k miles and after 1500 miles my avg. mileage is up 1.9 mpg. on multiple identical 500 mile trips before the virus.
O2 sensors are now on my maint. replacement list at 80k miles on my fleet.
No codes or detectable issues with the old ones either.
100k miles on them. Bank 2 reads .7 volts, bank 1 is reading .2 - .4v
 

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Delayed response and heater codes I'd change the O2 sensor at your mileage. Heaters are there to get sensors up to temp. faster so system goes closed loop for faster emissions compliance so bad heater will make for a slow responding sensor or make a weak one worse. Sensor not up to temp. will keep system in open loop which is a richer mixture to keep engine running, think of open loop as a electronic ''carburetor choke''. Sensor fails way more common than harness issues. Check for corrosion in connectors when changing them and harness no contacting exhaust, critter damage, etc. .
Upstream sensors control engine fueling, after cat just checks that cat is functioning and nothing else.
 

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Discussion Starter #12
Delayed response and heater codes I'd change the O2 sensor at your mileage. Heaters are there to get sensors up to temp. faster so system goes closed loop for faster emissions compliance so bad heater will make for a slow responding sensor or make a weak one worse. Sensor not up to temp. will keep system in open loop which is a richer mixture to keep engine running, think of open loop as a electronic ''carburetor choke''. Sensor fails way more common than harness issues. Check for corrosion in connectors when changing them and harness no contacting exhaust, critter damage, etc. .
Upstream sensors control engine fueling, after cat just checks that cat is functioning and nothing else.
Will that cause rough idle and stalling? Still trying to track this down. Majority of issue is at cold startup so o2 makes alot of sense. Also still confused why I dont get a code. I did have a p0506 pend while the rpms dropped but its generic and not to much to go by (I already knew my rpms were low lol) I do agree regardless 100k on a sensor is time to replace, I typically go by 80k miles to start considering replacing.
 

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P0506 CHEVROLET Meaning
The Idle Air Control valve is a Powertrain Control Module (PCM) controlled stepper motor located on the throttle body. The stepper motor drives a valve pintle which protrudes into a passage that bypasses the throttle plates. The PCM commands the Idle Air Control (IAC) valve pintle to extend to decrease the idle speed. The bypass air flow is reduced and the idle speed decreases as the pintle approaches its seat. The PCM retracts the IAC valve pintle away from its seat to increase the idle speed. The retracting of the IAC valve pintle allows more air to bypass the throttle plates. One of the PCMs uses for the IAC system is to maintain a desired idle speed.
 

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Discussion Starter #14
Scan tool is showing voltage drop at control module, 12v and the car stalls, give it a little gas and jumps back to 14.5v. Highway car runs around 14.8-15.1, idle at a light or in park is when the voltage drops (usually only if idling for 30min plus, car is on but not much actual driving is when the voltage starts to drop) Bad battery? I did clean off a ton of corrosion (it was blue) awhile back (battery leaking?) Gonna finally pick up a new one today. Also what grounds (locations) should I check for corrosion?
 

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Could be weak battery or connections. I would check voltage at the battery with a meter to confirm what scan tool sees.
Battery strong and stable is a priority in todays vehicles. Since voltage goes as high as it does seems like alt. is working fine. Load test on battery is the only way to confirm it's health and even then battery could be bad. In the last 10 yrs. I've had 3 batteries fail with intermittent internal connector issues. Symptom was no start, smack battery and headlights would come back on and vehicle would start. I'll confess that it was so weird and erratic I was looking skyward for passing over UFO's. LOL
2 batteries in my old Sable and one in my Tahoe. 2 Duracraps and one DieFast battery. They would always load check OK when carried into the store after being pulled out.
 

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Discussion Starter #16
Could be weak battery or connections. I would check voltage at the battery with a meter to confirm what scan tool sees.
Battery strong and stable is a priority in todays vehicles. Since voltage goes as high as it does seems like alt. is working fine. Load test on battery is the only way to confirm it's health and even then battery could be bad. In the last 10 yrs. I've had 3 batteries fail with intermittent internal connector issues. Symptom was no start, smack battery and headlights would come back on and vehicle would start. I'll confess that it was so weird and erratic I was looking skyward for passing over UFO's. LOL
2 batteries in my old Sable and one in my Tahoe. 2 Duracraps and one DieFast battery. They would always load check OK when carried into the store after being pulled out.
I've seen some odd battery behavior as well. The few voltage issues I have (no cel) seem to just point at the battery. Car turns over quick even after sitting for a few days. I'm probably overthinking it and just need to grab a new battery already, it's been cold and raining so I've been unmotivated to get to it. In the meantime I'm just reading up on issues and that's not always the thing to do lol.

headlights take a quick dim with power windows, seems normal. Iffy voltage at 02 sensors, could be a ground but batt makes sense. Evap purge voltage reads a tad off, again could be battery. From what I understand the alt needs help from the batt at idle and that's where I run into issues, long idle times. The sensitivity in cars these days seems to leave a very low tolerance in voltage.
 

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Could be weak battery or connections. I would check voltage at the battery with a meter to confirm what scan tool sees.
Battery strong and stable is a priority in todays vehicles.

Several people on this forum and else where who noticed a flurry of CEL codes (sometimes quite unrelated) have had the real problem being a failing battery.
 

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Agree. . . . battery - - battery - - battery.
 

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Discussion Starter #19
Replaced the battery (old one was tested and shot) now I have no voltage on o2 bank 1 sensor 1
 

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Tank, what are the voltage readings on each of the 4 pins of your O2 bank 1 sensor 1 ? The O2 sensor heater circuit should have Battery voltage on pin D , and a controlled path to ground via the ECM on pin E , both must be tested with the engine running.
 
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