Thread: A little annoyance

Ok so now my trusty td5 has developed another small fault
when starting temp gauge overheat light comes on and gauge at rest
and stays that way
Restart and all is normal.
Does not do it all the time .
Not loosing coolant or overheating.
thinking electrical or gauge has anybody else had this?
And what did they do to remedy this
Not going to just fit aftermarket temp warning

check the connector and exposed wiring to the engine coolant temp(ECT) sensor... if they look good replace the sensor to rule it out cos it's the first suspect:

Originally Posted by ENGINE MANAGEMENT SYSTEM - TD5 - DESCRIPTION AND OPERATION 18-1-15

The ECT sensor can fail the following ways or supply incorrect signal:
l Sensor open circuit.
l Short circuit to vehicle supply.
l Short circuit to earth.
l Incorrect mechanical fitting.
l Signal fixed above 40 °C (104 °F) not detected.
l Signal fixed below 40 °C (104 °F) not detected.

In the event of an ECT sensor signal failure any of the following symptoms may be observed:
l Difficult cold start.
l Difficult hot start.
l Driveability concerns.
l Instrument pack temperature warning illuminated.
l Temperature gauge reads excessively hot.
l Temperature gauge reads excessively cold.
In the event of component failure the ECM calculates coolant temperature from the fuel temperature sensor signal. If
this occurs, the limit engine operation if coolant temperature is too high becomes inoperative.
The MIL will not illuminate in an ECT sensor failure.

if no joy unfortunately there's a bad connection somewhere between the sensor and the engine ECU...let's hope not... buy only genuine sensor cos it's very important part of the management and a low quality aftermarket might cause all kind of troubles


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