dtc P06DA: open oil pump solenoid circuit

[persistent]

after replacing the camshaft and oil pump, i'm getting dtc P06DA, which is an open circuit for the oil pressure control solenoid. since i have the oil pan removed atm, i'm keen to get this dtc resolved prior to closing the oil pan, in case i need access to resolve the matter.

to check the wiring, i have tested for continuity and resistance from the 2 pin plug for the solenoid under the oil pump to the main harness landing at the left side of the engine bay and found that 1 conductor shows 0.0 ohms while the other shows 5.5 ohms. i have also tested all 3 segments of the cable for resistance - (1) oil pump solenoid to right front cover, (2) right front cover to lower left front cover, and (3) lower left front cover to main harness landing - and i have found the only section with a resistance measuring over 0.2 ohms is 1 conductor in section 3, which measures as 5.5 ohms.

to test the wiring, i have followed debug steps i found online. the test results are as follows:

- step 1 - clearing dtc does not work, it immediately reappears
- step 2 - confirmed no short to voltage
- step 3 - disconnected main harness containing the solenoid pins, confirmed no short to ground
- step 4 - i'm a bit confused about exactly what this step is testing, but i think it's testing for continuity/resistance of wiring between the sensor (solenoid) and the control module. this is where i'm getting 1 conductor with resistance of 5.5 ohms, which is greater than the 3 ohm threshold they cite.

is this 5.5 ohm resistance enough to trigger p06da, or is this not the issue?

given that i've narrowed down the high resistance to a particular section of cabling, what are the next steps for testing, e.g. backprobe the relevant pins on each end of the cable to rule out a damaged pin receiver?

 

[OR VietVet]

If you can get past this guys rambling, this video might help:

 

[persistent]

lol. i skimmed through this video previously because it was so annoying and low content.

giving it a closer rewatch per your recommendation.

 

[persistent]

not sure what i've managed to do here, but i cannot get the engine start button to work anymore. no lights of any kind will turn on in the vehicle. i guess disconnecting the big wiring harness was tempting fate for me.

i may have reconnected the (c2?) wiring harness without disconnecting the negative battery terminal. the battery seems fine. i checked all the engine-side fuses and none have blown.

any ideas on what else to try to get the electrical working again?

 

[OR VietVet]

"the battery seems fine"? Connections at the battery?

 

[persistent]

to clarify re battery and fuses:

- battery has charge and ~12v output
- tested continuity across all the integrated battery-side fuses under the battery cover that connect to the positive terminal
- the battery has been connected and disconnected while i was testing the wiring for the oil pump solenoid by disconnecting the negative terminal
- tested continuity across all the fuses in the engine fuse box on the left side of the engine compartment
- have not tested any relays in the engine fuse box yet

while battery connected, there is no response when pressing start engine button. this happened between my having the wire harness disconnected to test continuity and resistance in the wiring between the control module and the solenoid and reconnecting it. i had disconnected the harness without event while the battery was disconnected, so i think it's likely i accidentally connected the harness while the battery was connected. i'm concerned that i have either fried the ecm or wedged it into some state that it cannot be revived from, e.g. i have seen reports of a "crash mode" that is difficult to get out of.

i have left the battery disconnected overnight and am charging it using a charger.

 

[persistent]

looks like i spoke too soon re battery health.

i've started fresh this morning and the battery was showing 5v when connected. i've disconnected both terminals and see 11.8v on the battery. i'm attempting to charge it for a bit, and if it doesn't hold a charge, i'll have to get another one. a battery out test with a battery tester says to replace the battery, but i will give it a charge and see if it improves at all over the next 24 hrs.

i may have shorted the battery to ground by accident because i have the positive lead that attaches to the alternator loose in the engine compartment.

 

[OR VietVet]

looks like i spoke too soon re battery health.

i've started fresh this morning and the battery was showing 5v when connected. i've disconnected both terminals and see 11.8v on the battery. i'm attempting to charge it for a bit, and if it doesn't hold a charge, i'll have to get another one. a battery out test with a battery tester says to replace the battery, but i will give it a charge and see if it improves at all over the next 24 hrs.

i may have shorted the battery to ground by accident because i have the positive lead that attaches to the alternator loose in the engine compartment.

Exactly why I reacted to the "battery seems fine" comment. Personally, I always want to know about that battery. Little buggers can be a PITA sometimes.

 

[persistent]

the wiring from the ecm to the solenoid seems fine apart from the anomalously high wiring resistance of 5.5 ohms on 1 conductor.

i replaced my oil pump recently, and i had the old one on hand. i had pulled off the old solenoid from the old pump and had it plugged into the connector for the solenoid to see what would happen. apparently, that created a short to ground, draining the battery. i recharged the battery and have reinstalled it. given that i was able to drain the battery by accidentally shorting to ground at the solenoid sensor, i think it's safe to say the wiring is in acceptable shape. i'm seeing a resistance of about 6.5 k ohms between positive and negative battery leads once i remove that old solenoid.

is there a good way for me to test that the solenoid from the new pump works properly before i reinstall the oil pan? i couldn't find anything in either the scan tool i have (launch x431) or hp tuners that would allow me to manually activate the solenoid. when i seat the connector into the solenoid and check dtcs, it keeps showing the open circuit error for the solenoid, which doesn't create confidence the dtc will clear after i close the engine up. i'm concerned the solenoid that came with the new pump is bad, and i would really like to avoid closing everything up, only to have to pull it all apart again.

my experience with solenoids in other contexts is that you can measure their resistance to confirm they're working properly, e.g. irrigation valve solenoids. if the resistance is too high or too low, the solenoid is toast and needs to be replaced. in the context of hvac, a reversing valve solenoid will make a loud audible click as it flips on. i'm hoping i can do some similar confirmations before closing the engine up, and if i cannot get these confirmations, i'll have to pull the water pump, vacuum pump, balancer, and timing cover (again).

 

[persistent]

i'm being polite when i say i'm "not a fan" of how gm licenses their software.

am i right to assume that it is a requirement to have mdi 2 interface + gds2 software + tech2win software to be able to scan for dtcs and do bidirectional tests, e.g. manually activate this solenoid?

that said, i'm not at all keen on using possibly-begremlined CN hacks to work around the licensing either.