Signal Too High
Signal too high
Checking the evaporator temperature
- Ignition on.
Check that the evaporator temperature is within its permitted range. If the climate control system has not been running and the engine has cooled down, the temperature should be the same as the outside temperature.
If temperature is now OK the fault was caused by loose connections in the connectors.
Are the temperatures correct?
Yes - Checking connectors and wiring
No - Checking the evaporator temperature sensor
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Checking the evaporator temperature sensor
- Ignition off.
Check that the control module receives a correct value from the evaporator temperature sensor by measuring its resistance and comparing with the values in the table.
Measure the resistance between control module terminals #B1(#1) and #B15 (#15). This value must correspond with the resistance of the evaporator temperature sensor.
Other information:
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box, Climate Control Module (CCM)
- To access or replace the control module, see
- For resistance values, see Component resistance values [1][2]Electrical Specifications.
Is the resistance correct?
Yes - Checking connectors and wiring
No - Checking components and connectors
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Checking connectors and wiring
- Ignition on.
Check the signal cable between control module terminal #B1 and evaporator temperature sensor connector terminal #2 (#27). Check for an open-circuit. Check for a short-circuit to supply voltage.
Check the ground lead between control module terminal #B15 and evaporator temperature sensor terminal #3 (#28). Check for an open-circuit. Check for a short-circuit to supply voltage.
Remedy as necessary.
Other information:
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box, Climate Control Module (CCM)
- To access and replace the control module see
- To access or replace the evaporator temperature sensor, see Temperature sensor, evaporator, replacing Service and Repair
- For other values, see Signal description, climate control module (CCM), Connector B Signal Description, Climate Control Module (CCM), Connector B
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Verification
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Checking components and connectors
- Ignition off.
Checking the evaporator temperature sensor
Check the evaporator temperature sensor by measuring the resistance at the sensor connector between terminals #2 (#27) and #3 (#28).
The resistance must correspond to the value in the table.
Replace the evaporator temperature sensor if the resistance is not correct.
Checking the connector
Check the evaporator temperature sensor connector. Check for oxidation and contact resistance.
Check control module connector terminals #B1 (#1) and #B15 (15). Check for oxidation and contact resistance.
Remedy as necessary.
Other information:
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box, Climate Control Module (CCM)
- To access and replace the control module see
- To access or replace the evaporator temperature sensor, see Temperature sensor, evaporator, replacing Service and Repair
- For resistance values, see Component resistance values [1][2]Electrical Specifications.
Continue - Verification
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Checking connectors and wiring
- Ignition off.
Checking the connector
Check the evaporator temperature sensor connector. Check for loose connections. Check for oxidation and contact resistance.
Check control module connector terminals #B1 (#1) and #B15 (15). Check for loose connections. Check for oxidation and contact resistance.
Checking the wiring
Check the signal cable between control module terminal #B1 and evaporator temperature sensor connector terminal #2 (#27). Check for an intermittent open-circuit. Check for a short-circuit to supply voltage.
Check the ground lead between control module terminal #B15 and evaporator temperature sensor connector terminal #3 (#28). Check for an intermittent open-circuit. Check for a short-circuit to supply voltage.
Other information:
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box, Climate Control Module (CCM)
- To access and replace the control module see
- To access or replace the evaporator temperature sensor, see Temperature sensor, evaporator, replacing Service and Repair
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Verification
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Verification
Hint: After the repair it is necessary to check that the fault has been rectified.
- Ignition off.
- Connect the connectors, install the components, etc.
- Ignition on.
Check evaporator temperature.
The value should be between -40 °C and +85 °C (-40 °F and +185 °F).
Start engine and switch on air-conditioning unit.
Check that the value changes and remains between the given minimum and maximum values.
Does the value change?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFICATION FAILED - Information
VERIFIED - Fault Found
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Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - FAULT-TRACING FAILED
No - Attempt New Test
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Attempt New Test - Checking the evaporator temperature
FAULT-TRACING FAILED - No Fault Found
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Information
Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).
Do you want to view the information again?
Yes - Attempt New Test
No - Fault Found
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FAULT FOUND - Fault Found
Attempt New Test - Checking the evaporator temperature
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