Coolant Level Incorrect

Fault symptoms
The SID unit gives a warning of low coolant level despite correct level or does not give a warning despite low level.

Diagnostic help
The coolant level sensor can be read using the diagnostics tool.
The message COOLANT LEVEL LOW can be activated with the diagnostics tool.

Check the wiring harness
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short-circuits in the leads. Observe the multimeter, test lamp or diagnostics instrument during the test.

Diagnostic procedure

1. Check sensor grounding
^ Unplug the connector: coolant fluid level switch: (242).





^ Connect a test lamp to B+ and pin B of the female connector.





^ The lamp should light.





Test results OK?
YES
^ Go to point 2.
NO
^ Repair or replace the lead between pin B of the female connector and grounding point G40.
^ Go to point 4.

2. Check control module signal input
^ Connect the diagnostics tool to the vehicle and contact: SID.





^ Read status: coolant level sensor
^ The tester should show status: INACTIVE

Test results OK?
YES
^ Go to point 3.
NO
^ Repair or replace the lead between pin A of the female connector and pin 18 of the SID unit.
^ Go to point 4

3. Check the control module signal input (contd.)
^ Connect a jumper lead between pins A and B of the female connector.





^ Read status; coolant level sensor
^ he tester should show status: ACTIVE

Test results OK?
YES
^ Replace: coolant fluid level switch
^ Go to point 4
NO
^ Repair or replace the lead between pin A of the female connector and pin 18 of the SD unit
^ Go to point 4.

4. Final check
^ Clear the diagnostic trouble codes in all systems.





^ Carry out a function check





Test results OK?
YES
^ The steps taken to rectify the fault were correct.
NO
^ See "Before changing a control module" Before Changing A Control Module