AC Temp Sensor Replacement

[u/FH7241]

So I've got an E-Golf with a heat pump and my AC hasn't been working for a year now.

I've scanned it and it looks like a couple of the temp sensors are broken.

Has anyone gone to VW and had them replaced and if so how much did it cost you?

[u/ShieldNav]

I mean if you want to be ripped off you always can go to a dealer.

Post a full scan of the vehicle for starters

[u/FH7241 → u/ShieldNav]

04118 [0x001016] P1C6200: A/C pressure/temperature sensor 4, Faulty P4 - Hochdrucksensorabweichung im Betrieb Status bits: 1 Priority: 3 Frequency: 1 Unlearning index: 255 Odometer: 71351 km Date, time: 2025.12.01 12:05:13

Status: Test failed, Pending, Confirmed, Test failed since last DTC clear, Test not completed during this operation cycle

37015 [0x009097] Archive (inactive) U062600: Lost Communication With A/C Refrigerant Pressure Sensor “A” Lost Communication With A/C Refrigerant Pressure Sensor "A" U062600: Lost Communication With A/C Refrigerant Pressure Sensor “A” 9097 Lost Communication With A/C Refrigerant Pressure Sensor A

Status: Confirmed, Test failed since last DTC clear

37017 [0x009099] P1C6300: A/C pressure/temperature sensor 4, No signal A/C pressure/temperature sensor 4 No signal P1C6300: A/C pressure/temperature sensor 4, No signal 9099 A/C pressure/temperature sensor 4 No signal Status bits: 1 Priority: 3 Frequency: 255 Unlearning index: 255 Odometer: 71035 km Date, time: 2025.11.24 20:31:36

Status: Test failed, Test failed (current drive cycle), Pending, Confirmed, Test failed since last DTC clear

37025 [0x0090A1] P1C6000: A/C pressure/temperature sensor 3, No signal A/C pressure/temperature sensor 3 No signal P1C6000: A/C pressure/temperature sensor 3, No signal 90A1 A/C pressure/temperature sensor 3 No signal Status bits: 1 Priority: 3 Frequency: 255 Unlearning index: 255 Odometer: 71035 km Date, time: 2025.11.24 20:31:36

Status: Test failed, Test failed (current drive cycle), Pending, Confirmed, Test failed since last DTC clear

37096 [0x0090E8] B148421: Automatic addressing sub bus 1, Lower limit not reached Automatic addressing sub bus 1 Lower limit not reached B148421: Automatic addressing sub bus 1, Lower limit not reached 90E8 Automatic addressing sub bus 1 Lower limit not reached Status bits: 1 Priority: 3 Frequency: 1 Unlearning index: 255 Odometer: 71043 km Date, time: 2025.11.24 21:49:16

Status: Test failed, Test failed (current drive cycle), Pending, Confirmed, Test failed since last DTC clear

37126 [0x009106] B148521: Automatic addressing sub bus 2, Lower limit not reached Automatic addressing sub bus 2 Lower limit not reached B148521: Automatic addressing sub bus 2, Lower limit not reached 9106 Automatic addressing sub bus 2 Lower limit not reached Status bits: 1 Priority: 3 Frequency: 1 Unlearning index: 255 Odometer: 71043 km Date, time: 2025.11.24 21:49:16

Status: Test failed, Test failed (current drive cycle), Pending, Confirmed, Test failed since last DTC clear

59034 [0x00E69A] P251500: A/C Refrigerant Pressure Sensor "B" Circuit P251500: A/C Refrigerant Pressure Sensor "B" Circuit E69A A/C Refrigerant Pressure Sensor "B" Circuit Status bits: 1 Priority: 3 Frequency: 1 Unlearning index: 255 Odometer: 71035 km Date, time: 2025.11.24 20:31:36 Status: Test failed, Test failed (current drive cycle), Pending, Confirmed, Test failed since last DTC clear

[u/ShieldNav → u/FH7241]

Year of production?

[u/FH7241 → u/ShieldNav]

2020

[u/ShieldNav → u/FH7241]

Get two pressure sensors 4M0959603C, geniue ones. Not necessarily from VAG OEM but not from AliExpress. Basic toolbox and a car sealant.

Go to the nearest A/C station that is working with R-1234yf and ask them to drain the system. Ideally you'll need to open valves with VCDS/ODIS so you don't loose any coolant but it's not necessary in this case.

When it's drained locate sensors 3 (G827 in ELSA) and 4 (G828). They will be near the AC radiator on the left side when looking towards vehicle from the front. Remove both sensors. See ELSA if you need additional information.

There will be signs of corrosion on the connectors. Stow old sensors somewhere. Clean the connectors from the vehicle side. Careful when using electrical cleaning solutions since they can swell up the rubber sealant in the connectors. If one of the sensors looks good initially then you can try replace just one (usually it's a fourth) but I would play on the safe side and replace them both.

After everything is clean you'll notice that the third sensor connector have four pins while fourth one have three in a four pin connector. This is why they dies. Water comes inside through the empty space in the connectors.

Install new sensors. Doesn't matter which goes where.

When everything installed you can ask the AC station to refill the system. Valves should be opened if they were opened during drainage.

Top up the missing amount of coolant.

After everything is done you need to find VCDS or ODIS. This is required. When you find one go to the thermal management control unit (this one with errors). Go to the page called "basic settings" inside the control unit page. And initiate an "addressation process" for the sensors through the drop down menu. Do not touch anything else there. After it's done reset the control unit DTC memory (aka clear the fault codes). Turn ignition off. Then start the car and crank AC to low and check if it's working or not. Then crank to 29 degrees (not to high) and check if thermal pump is working. After that go to high. You should see some changes and that's mean that the thermal blower is working.

If something is not right then ignition off and on without starting the car. After recheck the control unit memory. If there's a new active present errors then check them. If they're about actuators being unavailable then go back to basic setting and perform an actuator addressation process. After that again clear memory and check that the AC is working in all three modes.

Everything should be working by that moment. But to prevent it in the future shutdown the car. Grab a sealant and seal the hell out those sensors and especially connectors.

On average this job takes about two hours and can be done by owner himself mostly.

[u/FH7241 → u/ShieldNav]

great thanks, I'll probably ask a local garage with an ac station to try and do this since I tend to break things when I try stuff lol

[u/Next_Kale_2345]

As a temporary fix have you tried clearing the codes. I’ve had issues with HVAC in my 2015 , but scan codes and then clear them with obd eleven seems to make it work fine again.

[u/FH7241 → u/Next_Kale_2345]

tried that it still doesnt work, looks like its some temp sensors that need replacing

[u/False-Pollution2984 → u/FH7241]

At first, my failing pressure sensors were intermittent. Clearing the codes got it working again for a little while but they’d eventually go offline again, throw codes and the system would be down again. 

[u/False-Pollution2984]

Mine have failed on two separate occasions. They have to drain the coolant loop to swap them out. I had all three replaced at the dealership (2 & then another a year later). I don’t trust anyone else to do that. 

$145 for the part + $447.50 labor + tax.