Temperature Sensor Replacing
21st June 2004
NOTE: THIS IS A BAM (225) ENGINE SENSOR PLEASE CHECK IF
YOURS IS DIFFERENT
APX (225) IS A DIFFERENT SENSOR PART NUMBER
A diagnosed fault at the AmD RR day meant that a temperature sensor could be sending incorrect signals to the ecu about the coolant temps.
The fault was:-
VAG-COM Version: Release 404.0-S
Control Module Part Number: 8N0 906 018 H
Component and/or Version: 1.8L R4/5VT G 0004
Software Coding: 10710
Work Shop Code: WSC 00088
Additional Info: TRUZZZ8N221022392 AUZ5Z0B1065062
1 Fault Found:
17704 - Error in Mapped Cooling System (usually temp Sensor or Thermostat)
P1296 - 35-10 - - - Intermittent
Other possible errors:-
16502 - Engine Coolant Temp. Sensor (G62): Signal too High
P0118 - 35-00 --
Readiiness 0010 0101
The symptoms of this small device are varied and wide:-
It can cause the ecu to cut back on boost,
It can cause soft limp mode and poor running.
It can make you feel you have a boost leak and
It can provide false reading that could cause lean or rich running.
It could cause strange dash temperature readings.
It is quite surprising how varied and dramatic an effect this sensor can have.
If you currently have a black temp sensor it would do no harm to change it for a later green one.
The following is a guide to changing it, make sure the engine is cool.
The replacement part is different and updated I'm told,
identified by it being green.(BAM ENGINES)
The unit is between the battery/airbox and engine block.
It sits a plastic hose joint and is a little difficult to see.
You should open the water reservoir cover and reseal it to
release any pressure.
Then pull the plastic circlip, its easy enough to do without tools.
Then withdraw the connector and sender, a few drops of water may come out but it will not flow out.
its easier to see the tab to pull on the connector that will disengage from the tooth, then disengage the sender.
Fit the new sender and o-ring to the connector and refit into
slide the plastic circlip back through the slot on the housing either side to lock the sender in place.
Then run the engine and check there are no leaks, take a drive
and check the sender again.
There should not be any need to have to top up coolant virtually none should have dropped out.
You "should" have the fault code reset with vagcom or at a dealer.
Note: the sender/o-ring does feel quite a flimsy fit and seal
in its housing for a high temp
and pressured cooling system but it seems to be working fine now!