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2017 P2517 P151C A/C Refrigerant Pressure Sensor B Circuit Low

8.5K views 16 replies 9 participants last post by  chadzu1  
#1 ·
I got this error on my 17' Volt Premier. Can't seem to be cleared out as it is a Perm.

So I figured maybe the Refrigerant Pressor Senor went bad so ordered exactly the same part and changed it and still no good. I checked the refrigerant pressure it is high like 60PSI so that's good no leak.

Is this another case of bad battery? The car battery mysteriously drained 2-3 months ago to like 9.31v and had to charge it back up to get the car working.

I checked my battery it registers 12.68v car not turned on.

Ran the AC for more than 15mins and still runs warm. Never had a car with this issue of recent years.
 
#3 ·
I suspect a wiring problem. Wire chafe through or broken somewhere.

Image


You got two of those going, which makes screen clip convenient. :) Anyway, P2517 is definitely electrical, and P151C is also TECHNICALLY electrical, though it's easily caused by other things, and you'll likely get asked about 12v age if there's no other stuff going on. But you got the other stuff going on: Low side pressure sensor ain't reading for some reason, and if you've already changed it, it's time to check the wiring for it.

At this point, I'm likely to suspect that P151C is consequential to the P2517, at least by cause. And it's not going away as a code because it won't even RUN that test (to see if it passes and can be unset) while the other code's conditions still exist.

I'm including the circuit test text not because I understand or expect it to be complete, but as guidance toward whether you think you want to continue solo or seek service.

Circuit/System Testing Vehicle OFF, all vehicle systems OFF, scan tool disconnected, and key removed from vehicle, disconnect the harness connector at the B1C A/C Low Side Pressure Sensor. It may take up to 10 min for all vehicle systems to power down.
1. Test for less than 10 Ω between the low reference circuit terminal 1 and ground. If 10 Ω or greater Vehicle OFF, disconnect the harness connector at the K114B Hybrid/EV Powertrain Control Module
2. 1. Test for less than 2 Ω in the low reference circuit end to end. If 2 Ω or greater, repair the open/high resistance in the circuit. If less than 2 Ω, replace the K114B Hybrid/EV Powertrain Control Module
2. 2. If less than 10 Ω
2. 3. Vehicle in Service Mode. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 2 and ground. If less than 4.8 V
2. 4. Vehicle OFF, disconnect the X1 harness connector at the K114B Hybrid/EV Powertrain Control Module 2.

1. Test for infinite resistance between the terminals listed below and ground. Terminal 63 Terminal 64
If less than infinite resistance, repair the short to ground on the circuit.
If infinite resistance
2. Test for less than 2 Ω in the 5 V reference circuit terminal 63 end to end. If 2 Ω or greater, repair the open/high resistance in the circuit. If less than 2 Ω, replace the K114B Hybrid/EV Powertrain Control Module 2.
3. If greater than 5.2 V
Vehicle OFF, disconnect the harness connector at the K114B Hybrid/EV Powertrain Control Module 2, vehicle in Service Mode.
1. Test for less than 1 V between the terminals listed below and ground.
Signal circuit terminal 25
Signal circuit terminal 31
Signal circuit terminal 50
5 V reference circuit terminal 63
5 V reference circuit terminal 64
If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K114B Hybrid/EV Powertrain Control Module 2.
2. If between 4.8 - 5.2 V Verify the scan tool Hybrid/EV Powertrain Control Module 2 A/C Low Side Pressure Sensor parameter is less than 0.1 V.
If 0.1 V or greater Vehicle OFF, disconnect the harness connector at the K114B Hybrid/EV Powertrain Control Module 2, vehicle in Service Mode.
1. Test for less than 1 V between the signal circuit terminal 3 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K114B Hybrid/EV Powertrain Control Module 2.
2. If less than 0.1 V 5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 2.
6. Verify the scan tool A/C Low Side Pressure Sensor parameter is greater than 4.8 V. If 4.8 V or less Vehicle OFF, remove the jumper wire and disconnect the X1 harness connector at the K114B Hybrid/EV Powertrain Control Module 2.
1. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit.
2. If infinite resistance
Test for less than 2 Ω in the signal circuit end to end. If 2 Ω or greater, repair the open/high resistance in the circuit. If less than 2 Ω, replace the K114B Hybrid/EV Powertrain Control Module 2.
3. If greater than 4.8 V 8. Test or replace the B1C A/C Low Side Pressure Sensor. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. HVAC Component Replacement Reference Control Module References for control module replacement, programming and setup
 
#5 ·
I suspect a wiring problem. Wire chafe through or broken somewhere.

View attachment 176699

You got two of those going, which makes screen clip convenient. :) Anyway, P2517 is definitely electrical, and P151C is also TECHNICALLY electrical, though it's easily caused by other things, and you'll likely get asked about 12v age if there's no other stuff going on. But you got the other stuff going on: Low side pressure sensor ain't reading for some reason, and if you've already changed it, it's time to check the wiring for it.

At this point, I'm likely to suspect that P151C is consequential to the P2517, at least by cause. And it's not going away as a code because it won't even RUN that test (to see if it passes and can be unset) while the other code's conditions still exist.

I'm including the circuit test text not because I understand or expect it to be complete, but as guidance toward whether you think you want to continue solo or seek service.

Circuit/System Testing Vehicle OFF, all vehicle systems OFF, scan tool disconnected, and key removed from vehicle, disconnect the harness connector at the B1C A/C Low Side Pressure Sensor. It may take up to 10 min for all vehicle systems to power down.
1. Test for less than 10 Ω between the low reference circuit terminal 1 and ground. If 10 Ω or greater Vehicle OFF, disconnect the harness connector at the K114B Hybrid/EV Powertrain Control Module
2. 1. Test for less than 2 Ω in the low reference circuit end to end. If 2 Ω or greater, repair the open/high resistance in the circuit. If less than 2 Ω, replace the K114B Hybrid/EV Powertrain Control Module
2. 2. If less than 10 Ω
2. 3. Vehicle in Service Mode. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 2 and ground. If less than 4.8 V
2. 4. Vehicle OFF, disconnect the X1 harness connector at the K114B Hybrid/EV Powertrain Control Module 2.

1. Test for infinite resistance between the terminals listed below and ground. Terminal 63 Terminal 64
If less than infinite resistance, repair the short to ground on the circuit.
If infinite resistance
2. Test for less than 2 Ω in the 5 V reference circuit terminal 63 end to end. If 2 Ω or greater, repair the open/high resistance in the circuit. If less than 2 Ω, replace the K114B Hybrid/EV Powertrain Control Module 2.
3. If greater than 5.2 V
Vehicle OFF, disconnect the harness connector at the K114B Hybrid/EV Powertrain Control Module 2, vehicle in Service Mode.
1. Test for less than 1 V between the terminals listed below and ground.
Signal circuit terminal 25
Signal circuit terminal 31
Signal circuit terminal 50
5 V reference circuit terminal 63
5 V reference circuit terminal 64
If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K114B Hybrid/EV Powertrain Control Module 2.
2. If between 4.8 - 5.2 V Verify the scan tool Hybrid/EV Powertrain Control Module 2 A/C Low Side Pressure Sensor parameter is less than 0.1 V.
If 0.1 V or greater Vehicle OFF, disconnect the harness connector at the K114B Hybrid/EV Powertrain Control Module 2, vehicle in Service Mode.
1. Test for less than 1 V between the signal circuit terminal 3 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K114B Hybrid/EV Powertrain Control Module 2.
2. If less than 0.1 V 5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 2.
6. Verify the scan tool A/C Low Side Pressure Sensor parameter is greater than 4.8 V. If 4.8 V or less Vehicle OFF, remove the jumper wire and disconnect the X1 harness connector at the K114B Hybrid/EV Powertrain Control Module 2.
1. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit.
2. If infinite resistance
Test for less than 2 Ω in the signal circuit end to end. If 2 Ω or greater, repair the open/high resistance in the circuit. If less than 2 Ω, replace the K114B Hybrid/EV Powertrain Control Module 2.
3. If greater than 4.8 V 8. Test or replace the B1C A/C Low Side Pressure Sensor. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. HVAC Component Replacement Reference Control Module References for control module replacement, programming and setup
From a few of your recommendations there, it seems the K114B Hybrid/EV Powertrain Control Module 2 is a common problem here. I see the part on ebay for around $100, can this item be swapped out easily and doesn't need to be programmed for the VIN? I guess unplug the battery and swap it out and power on and see if that solves it.
 
#14 ·
I got this error on my 17' Volt Premier. Can't seem to be cleared out as it is a Perm.

So I figured maybe the Refrigerant Pressor Senor went bad so ordered exactly the same part and changed it and still no good. I checked the refrigerant pressure it is high like 60PSI so that's good no leak.

Is this another case of bad battery? The car battery mysteriously drained 2-3 months ago to like 9.31v and had to charge it back up to get the car working.

I checked my battery it registers 12.68v car not turned on.

Ran the AC for more than 15mins and still runs warm. Never had a car with this issue of recent years.
Hey Kevin--

I saw that you mentioned you changed out the AC sensor that went bad. I can't seem to find the location of said sensor. Do you know where it is located at in the car? Google isn't helping me.

Thanks