coolant temp gauge not working, co

passatTDI2005

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Sep 15, 2015
Location
Yardley, PA
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2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
Hello everyone,
I own 2 B5.5 2004 and 2005 passat wagons ( some of you may recall my previous posts.) my 2004, temperature gauge has stopped moving from the off position. So it does not show any temperature reading. I have check the fuses and believe they're all Good. the car operates fine in long drives so I believe the thermostat and the cooling system is working fine. there is air in the heating core and gargling sounds are regular and frequent in the dashboard. I have tried to remove the air out of heater core several times, by following the prescribed procedure in this B 5.5 thread posts, but been unsuccessful. the coolant in the reservoir does go a little bit low occasionally so there may be a leak somewhere, but not significant amount.
How do I proceed to diagnose Further ? what should I check next?
thank you in advance for your time and thoughts.
Aria
 

PickleRick

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Nov 29, 2017
Location
Greenville sc
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05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
Its most likely the cct. It's a common issue on these. A pita to change but not a hard diy job.
 

passatTDI2005

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Sep 15, 2015
Location
Yardley, PA
TDI
2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
temp gauge inop. , CCT related?

What is CCT? ( sorry I couldn't find a relevant description on Google)
And is possible to test it, verify it failed?
Thank you


After some searches, YouTube ...

I think CCT means cam chain tensioner. Not sure.
how would CCT be related to temperature gauge in dashboard not operating ?
 
Last edited:

PickleRick

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Nov 29, 2017
Location
Greenville sc
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05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
The coolant temp sending unit. The one between the engine and fire wall, not the one near the radiator.

It sends 2 signals out, one to ecu and one to temp gauge.
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Are you able to scan the car and see if the ECU has the correct temperature reading?
 

afarfalla

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Joined
Nov 6, 2006
Location
sugar land tx
TDI
05 Passat sedan and 05 wagen
before you do anything follow Windex's advice and scan for temp reading. the sending unit is at the back of the engine under the tandem pump. if your oriental your hands may fit.
 

passatTDI2005

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Sep 15, 2015
Location
Yardley, PA
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2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
here are the faults that were reported. two are related to temperature sensor. Please let me know what they mean, in terms of what has failed.

5 Faults Found:
17057 - Cylinder 3 Glow Plug Circuit (Q12)
P0673 - 000 - Electrical Fault
Freeze Frame:
RPM: 0 /min
Torque: 202.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 11.40 V
Bin. Bits: 00001000
Temperature: 15.3°C
Bin. Bits: 00110000

16502 - Engine Coolant Temp. Sensor (G62)
P0118 - 000 - Signal too High
Freeze Frame:
RPM: 2436 /min
Torque: 258.0 Nm
Speed: 22.0 km/h
Load: 60.0 %
Voltage: 13.76 V
Bin. Bits: 00001000
Temperature: -0.9°C
Temperature: 70.2°C

17056 - Cylinder 2 Glow Plug Circuit (Q11)
P0672 - 000 - Electrical Fault
Freeze Frame:
RPM: 1848 /min
Torque: 98.0 Nm
Speed: 46.0 km/h
Load: 23.1 %
Voltage: 13.91 V
Bin. Bits: 00001000
Temperature: 4.5°C
Bin. Bits: 10110000

17055 - Cylinder 1 Glow Plug Circuit (Q10)
P0671 - 000 - Electrical Fault
Freeze Frame:
RPM: 0 /min
Torque: 238.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 11.25 V
Bin. Bits: 00001000
Temperature: 1.8°C
Bin. Bits: 00110000

16705 - Engine Speed Sensor (G28)
P0321 - 000 - Implausible Signal
Freeze Frame:
RPM: 210 /min
Torque: 258.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 11.48 V
Bin. Bits: 00001000
Idle Stabilization: 0.0°KW
RPM: 63 /min


3 Faults Found:
01039 - Coolant Temperature Sensor (G2)
64-10 - Not Currently Testable - Intermittent
01039 - Coolant Temperature Sensor (G2)
30-10 - Open or Short to Plus - Intermittent
01304 - Radio
49-00 - No Communications
 

afarfalla

Veteran Member
Joined
Nov 6, 2006
Location
sugar land tx
TDI
05 Passat sedan and 05 wagen
g62 is, I believe the one at the back of the engine, you may have a green one which needs to be changed to a black one or vice versa. Make sure your battery voltage is just under 14v, clear all the codes and see what comes back.
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Codes are good, but do you have a coolant temp sensor reading that agrees with the actual temperature of the engine?

The sensor is a bit of a pain to replace, but is relatively cheap. I would scan the engine data to see if the CTS reads properly, and then make decision to replace.

I would likely replace no matter what, as the price of the sensor, o-ring and retainer clip is minimal.

If that doesn't solve the issue, you would likely be into some sort of wiring repair.
 
Last edited:

afarfalla

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Joined
Nov 6, 2006
Location
sugar land tx
TDI
05 Passat sedan and 05 wagen
the 5 readings you posted look like they were in the ECU's memory, they look random. Clear out your codes get the car up to temp and read them again.
 

passatTDI2005

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Sep 15, 2015
Location
Yardley, PA
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2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
Thanks for the ideas and suggestions:
here is coolant temp. sensor code, after car was running and warmed up in 80's temperature.


So please help decipher and let me know what to do next.




16502 - Engine Coolant Temp. Sensor (G62)
P0118 - 000 - Signal too High
Freeze Frame:
RPM: 1281 /min
Torque: 46.0 Nm
Speed: 0.0 km/h
Load: 10.2 %
Voltage: 13.45 V
Bin. Bits: 00001000
Temperature: 75.6°C
Temperature: 75.6°C




Other fault codes:


Address 01: Engine Labels: 038-906-016-BHW.lbl
Part No SW: 038 997 016 T HW: 028 101 198 2
Component: R4 2,0L EDC G000AG 0314
Revision: 12345678 Serial number: VWZ7Z0D0895815
Coding: 0150034
Shop #: WSC 06103 444 84163
VCID: 2F661398BD13A83A09-513C

6 Faults Found:
16725 - Camshaft Position Sensor (G40)
P0341 - 000 - Implausible Signal - Intermittent
Freeze Frame:
RPM: 210 /min
Torque: 124.0 Nm
Speed: 0.0 km/h
Load: 100.0 %
Voltage: 10.79 V
Bin. Bits: 00001000
Idle Stabilization: 0.0°KW
(no units): 32.0

16512 - Coolant Thermostat Valve (N214)
P0128 - 000 - Temperature below Control Range
Freeze Frame:
RPM: 1848 /min
Torque: 136.0 Nm
Speed: 50.0 km/h
Temperature: 53.1°C
Fuel Consump.: 5.40 l/h
Temperature: 36.9°C
Temperature: 36.9°C
Absolute Pres.: 1234.2 mbar

17055 - Cylinder 1 Glow Plug Circuit (Q10)
P0671 - 000 - Electrical Fault - Intermittent
Freeze Frame:
RPM: 0 /min
Torque: 174.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 12.08 V
Bin. Bits: 00001000
Temperature: 27.0°C
Bin. Bits: 00110000

17056 - Cylinder 2 Glow Plug Circuit (Q11)
P0672 - 000 - Electrical Fault - Intermittent
Freeze Frame:
RPM: 0 /min
Torque: 174.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 12.08 V
Bin. Bits: 00001000
Temperature: 27.0°C
Bin. Bits: 00110000

17058 - Cylinder 4 Glow Plug Circuit (Q13)
P0674 - 000 - Electrical Fault - Intermittent
Freeze Frame:
RPM: 0 /min
Torque: 174.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 12.08 V
Bin. Bits: 00001000
Temperature: 27.0°C
Bin. Bits: 00110000

16485 - Mass Air Flow Sensor (G70)
P0101 - 000 - Implausible Signal
Freeze Frame:
RPM: 1722 /min
Torque: 0.0 Nm
Speed: 93.0 km/h
Temperature: 39.6°C
(no units): 24.0
(no units): 1.13
Temperature: 78.3°C



 

afarfalla

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Joined
Nov 6, 2006
Location
sugar land tx
TDI
05 Passat sedan and 05 wagen
6 faults found...battery voltage 10.79?? its low and will effect readings, the car won't start with a bad cam sensor. Get mirror. look at coolant flange under tandem pump at the back of the engine, sensor lives there, change it and the coolant flange if you haven't already. Get a good battery clear the codes and do what windex says in post 9
 
Last edited:

afarfalla

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Joined
Nov 6, 2006
Location
sugar land tx
TDI
05 Passat sedan and 05 wagen
my thinking is that the battery is weak so during crank ECU was not satisfied with results so it thru the code, but sensor is OK. The Glo-plug readings were done with key on only, battery reads 12 volts? Low? The g62 code was done with engine running so it makes sensor suspect. If he would read vag engine temp results should point to g62 depending on reading? Your thoughts
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Live data - not stored codes.

What does the sensor read live vs the actual temperature of the engine?

An infrared temperature gun works well here.

If you don't have an infrared heat gun, then get the car to operating temperature, and let us know how long you can hold the upper rad hose (note - don't burn yourself).

if coolant temp = 212f, you wont be able to hold the hose at all (boiding temp) at 150 deg f, you can probably leave your hand on the upper hose almost indefinitely. at 175 f most folks would be able to hold the hose for a second or two unless your hands are made of asbestos.

again, don't burn yourself - try holding the upper rad hose when your scanner tells you (live data!) that the engine temp is 150 deg f through 170 f
 

passatTDI2005

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Sep 15, 2015
Location
Yardley, PA
TDI
2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
Hi all,
Update: i wanted to eliminate the potential of a weak battery causing electrical and stability, so I recharge the battery and make sure very strong charger was on battery when I start it the engine. Also I started the glow plugs and let few seconds go by before cranking the engine there for glow plugs might have been off by then. I have taken that reading. And will post it even though it does not live data. It shows the static Electric weather glow plugs when starters not engaged yet after that posting I will also post the running car stats on coolant temperature censor after the engine has ran for a while it's at temperature. The temperature reading for the hot top tube out of the radiator is 165° with infrared thermometer. Engine while after long
running, at idel 185ish..
Unfortunately I'll goet that data on next post (computer )
 

passatTDI2005

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Joined
Sep 15, 2015
Location
Yardley, PA
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2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
Status: Engine cool , battery been charging and on charger on, during turning ignition switch just on On. So to provide glow plugs good power. then few seconds wait before cranking the starter and engine on.

4 Faults Found:

16502 - Engine Coolant Temp. Sensor (G62)
P0118 - 000 - Signal too High
Freeze Frame:
RPM: 0 /min
Torque: 162.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 14.21 V
Bin. Bits: 00001000
Temperature: 32.4°C
Temperature: 32.4°C

17055 - Cylinder 1 Glow Plug Circuit (Q10)
P0671 - 000 - Electrical Fault
Freeze Frame:
RPM: 0 /min
Torque: 238.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 12.62 V
Bin. Bits: 00001011
Temperature: 2.7°C
Bin. Bits: 00110000

17056 - Cylinder 2 Glow Plug Circuit (Q11)
P0672 - 000 - Electrical Fault
Freeze Frame:
RPM: 0 /min
Torque: 238.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 12.62 V
Bin. Bits: 00001011
Temperature: 2.7°C
Bin. Bits: 00110000

17057 - Cylinder 3 Glow Plug Circuit (Q12)
P0673 - 000 - Electrical Fault
Freeze Frame:
RPM: 0 /min
Torque: 238.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 12.62 V
Bin. Bits: 00001011
Temperature: 2.7°C
Bin. Bits: 00110000


New different time reading :
Fault codes after engine running a long time upper Coolant tube 165' , engine 185's. Reading same as before ,then reset , only code for temp sensor showed up again :
16502 - Engine Coolant Temp. Sensor (G62)
P0118 - 000 - Signal too High
Freeze Frame:
RPM: 840 /min
Torque: 36.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 13.91 V
Bin. Bits: 00001000
Temperature: 75.6°C
Temperature: 75.6°C


Readiness: 0 0 1 1 1
 

passatTDI2005

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Joined
Sep 15, 2015
Location
Yardley, PA
TDI
2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
My apologies for multiple texts. Based on what i just posted, I think the temp on upper Coolant tube is about 74' Celsius, 165'F . Very close to temp sensor reading 75.6 C . Not sure if that's good, too low? Is something else in op ?
Thank you
 

afarfalla

Veteran Member
Joined
Nov 6, 2006
Location
sugar land tx
TDI
05 Passat sedan and 05 wagen
disregard glo-plug faults....battery has a weak cell...change g62 and flange, get new gasket for tandem pump. Your ready to go.
 

passatTDI2005

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Joined
Sep 15, 2015
Location
Yardley, PA
TDI
2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
Hello and Thank you all.
I posted Fault codes while Engine was in Operating Temp and running.

Windex- are the posted scans the "live data" you looking for? is ECU info what I posted or something else? ( Sorry I am not very familiar with VCDS scanner and its software)


If scan code shows Temp. 75.6' Celsius, is that from CTS or another Temp sensor? in otherwords, if temps are close to Top Radiator hose temp, then doesn't it mean that CTS is working? I'm trying to get a better understanding of the readings , so diagnose problem part and replace the faulty part .


Thanks again.


Aria
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
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05 B5V 01E FRF
Trying to get an idea of if the CTS is reading correctly by comparing its value (as viewed in live OBDII data or VCDS) to an actual temperature reading via an IR thermometer gun.

If the two agree (actual measured temp and temp read through the ECU) from cold to warmed up, then the CTS is not likely the culprit.

A place to start is that the coolant temp sensor reading in the ECU should be pretty close to ambient when the car is started in the morning after sitting overnight.

Have you been able to check that?
 

passatTDI2005

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Sep 15, 2015
Location
Yardley, PA
TDI
2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
Scan code for CTS after engine was at Operating temp and sat for few mintues while I was getting setup, then ran the engine a bit while taking the readings on Top Radiator hose 71' C or 160' F . outside Air temp about 25.5' C or 78' F

16502 - Engine Coolant Temp. Sensor (G62) P0118 - 000 - Signal too High Freeze Frame: RPM: 1407 /min Torque: 58.0 Nm Speed: 0.0 km/h Load: 13.7 % Voltage: 13.98 V Bin. Bits: 00001000 Temperature: 70.2°C Temperature: 70.2°C
What are the 2 Temp readings at 70.2' C? Are there 2 temp sensors?


Scan code for CTS engine in early a.m., after it cooled over night. I cleared the codes, did Not run the engine while taking the readings on Top Radiator hose 21' C or 69'F.
Outside Air temp about 20.7' C or 69' F
16502 - Engine Coolant Temp. Sensor (G62) P0118 - 000 - Signal too High Freeze Frame: RPM: 0 /min Torque: 188.0 Nm Speed: 0.0 km/h Load: 0.0 % Voltage: 11.93 V Bin. Bits: 00001000 Temperature: 20.7°C Temperature: 20.7°C

So, From what I have learned during this postings from info provided, It seems like
the CTS agrees closely with the Top Radiator Hose temp measurement with my IR Thermometer.

maybe the CTS is not the problem?

I have checked all the fusees. but which one would be for the Temp gauge in dashboard or related to this problem?
Maybe I should take them out and swap them with new?

where else do I diagnose? wiring ?

Thanks

Aria
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Goodness sake.

Live Data.

Live Data.

Live Data.

Stop guessing by relying only on stored codes.

Read the data at the ECU and see what the temp sensor reading is cold, then measure and compare as the car warms up.

You can obtain an ELM 327 dongle and torque for android for $10 if your current tool will not show live data.
 

afarfalla

Veteran Member
Joined
Nov 6, 2006
Location
sugar land tx
TDI
05 Passat sedan and 05 wagen
Goodness sake.

Live Data.

Live Data.

Live Data.

Stop guessing by relying only on stored codes.

Read the data at the ECU and see what the temp sensor reading is cold, then measure and compare as the car warms up.

You can obtain an ELM 327 dongle and torque for android for $10 if your current tool will not show live data.
He may not know how to do it?
 

passatTDI2005

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Joined
Sep 15, 2015
Location
Yardley, PA
TDI
2005 PASSAT Wagon (green) , 2004 Passat Wagon (black)
Hey guys,
apoloies for not understanding what data you wanted to see. I am new the this diag tool:
HEX + CAN made by ROSS TEch and VCDS Software.
THAT is WHY I asked " Am I providing you what you looking for?
so after some searching , I "Think" the Measure Block in Engine section of diag software is providing "LIVE DATA". Please advice if not correct, to where I should collect LIVE DATA.

so Warm engine last night: Top Rad. hose reads 73.1' Celcius


Address 01: Engine (038 997 016 T)

21:46:29 Group 001: Basic Functions - Injection Quantity
1365 /min Engine Speed (G28)
8.8 mg/str Injection Quantity
7.1∞KW Supply Duration
73.8∞C Coolant Temperature (G62)

21:46:29 Group 002: Basic Informations - Idle Speed
1365 /min Engine Speed (G28)
12.9 % Throttle Position Sensor
0 00 0 Operating Conditions
73.8∞C Coolant Temperature (G62)

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: Engine (038 997 016 T)

21:47:05 Group 001: Basic Functions - Injection Quantity
1365 /min Engine Speed (G28)
8.8 mg/str Injection Quantity
7.1∞KW Supply Duration
73.8∞C Coolant Temperature (G62)

21:47:05 Group 002: Basic Informations - Idle Speed
1365 /min Engine Speed (G28)
12.9 % Throttle Position Sensor
0 00 0 Operating Conditions
73.8∞C Coolant Temperature (G62)

21:47:05 Group 003: Basic Functions - Exhaust Gas Recirculation (EGR)
1365 /min Engine Speed (G28)
235.0 mg/str Mass Air Flow (specified)
240.0 mg/str Mass Air Flow (actual)
71.8 % EGR Duty Cycle

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: Engine (038 997 016 T)

21:47:08 Group 001: Basic Functions - Injection Quantity
1365 /min Engine Speed (G28)
8.8 mg/str Injection Quantity
7.1∞KW Supply Duration
73.8∞C Coolant Temperature (G62)

21:47:08 Group 002: Basic Informations - Idle Speed
1365 /min Engine Speed (G28)
12.9 % Throttle Position Sensor
0 00 0 Operating Conditions
73.8∞C Coolant Temperature (G62)

21:47:08 Group 003: Basic Functions - Exhaust Gas Recirculation (EGR)
1365 /min Engine Speed (G28)
235.0 mg/str Mass Air Flow (specified)
230.0 mg/str Mass Air Flow (actual)
70.6 % EGR Duty Cycle



This Morniing Cooled engine: Top Rad. hose Temp : 23 C when engine was off and went up to 30 C after engine was running for couple of mintues while I was getting LIVE DATA.


Address 01: Engine (038 997 016 T)

07:30:05 Group 001: Basic Functions - Injection Quantity
1365 /min Engine Speed (G28)
9.1 mg/str Injection Quantity
6.6∞KW Supply Duration
32.4∞C Coolant Temperature (G62)

07:30:05 Group 002: Basic Informations - Idle Speed
1386 /min Engine Speed (G28)
13.3 % Throttle Position Sensor
0 00 0 Operating Conditions
32.4∞C Coolant Temperature (G62)

07:30:05 Group 003: Basic Functions - Exhaust Gas Recirculation (EGR)
1386 /min Engine Speed (G28)
265.0 mg/str Mass Air Flow (specified)
255.0 mg/str Mass Air Flow (actual)
75.0 % EGR Duty Cycle
 

MEgearhead

Veteran Member
Joined
Aug 6, 2016
Location
Virginia
TDI
B5.5, 4L, 4G
Your answer was in post #4. While there is one physical part ( 059 919 501A), it is actually two sensors; one for the engine, and one for the instruments. Compare address 01 (engine) measuring block 001-4 (coolant temp G62) against address 17 (instruments) measuring block 003-1 (coolant temp). They are likely different. If so, you need to replace the dual sensor. Be sure to replace the o-ring with it. Don't ask me how I know.
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
sit car overnight

connect VCDS, turn key on, do not start engine

Go to group 1 and write down engine coolant temperature reading. Take your IR gun and read the temp of the hard metal coolant pipe on the driver's side of the engine, as close to the engine as possible. Write down that value next to the other value.

Start the engine, wait one minute, and do the same - record both readings below the first two. Do this once a minute until the car warms fully.

You should end up with two columns of numbers, one column increasing engine temp readings, the other should be temp readings from your IR temp gun.

If the numbers mostly match all the way down, then the Temp sensor is reading correctly and your fault is elsewhere. if the #'s don't agree, then you have a sensor or wiring issue.
 
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