Checking components and wiring
The male and female pins on the electronic throttle unit connectors are gold plated. Great care must be taken when measuring. Damage to the gold plating can result in operating difficulties.
- Ignition off
- Check the throttle unit and engine control module (ECM) connectors. Check for contact resistance and oxidation.
Check the resistance value of the damper motor winding in the throttle unit. Take readings between throttle unit terminals #1 and #4 (component side). Check for an open-circuit. Check for a short-circuit.
NOTE:The resistance of the motor winding in the damper motor is very low.
Check the cable (+) for the damper motor between engine control module (ECM) terminal #A35 (#A35) and throttle unit terminal #4 (cable harness side). Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Check the cable (-) for the damper motor between engine control module (ECM) terminal #A36 (#A36) and throttle unit terminal #1 (cable harness side). Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Also check the damper motor cables (+) and (-). Check for a short-circuit to each other.
Check that the shutter in the throttle unit is not blocked or sticking. Clean as necessary.
Remedy as necessary.
Other information:
- See Connecting the breakout box
- For information about signals:
- For turbocharged engines -2001, see Signal specification
- For turbocharged engines 2002, see Signal specification
- For B5254T2 -2004, see Signal description
- For B5204T5, B5234T3, B5234T7 and B5244T3 -2004, see Signal specification (B5204T5, B5234T3, B5234T7 and B5244T3 -2004)
- For B5254T4 2004, see Signal specification (B5254T4 2004)
- For turbocharged engines 2005-, see Signal specification .
- For resistance values:
- For turbocharged engines 2001, see Component specifications .
- For turbocharged engines 2002, see Component specifications .
- For turbocharged engines 2003-, see Component specifications .
- For B5254T4 2004-, see Component specifications .
- For normally aspirated engines 1999-, see Component specifications
- To access or replace the throttle unit:
- For B5xx4T -2001, see Throttle body (electronic throttle module (ETM)), replacing .
- For B5xx4T 2002-2004, see Replacing the throttle body (TB) .
- For B5xx4T 2005-, B5244T5 and B5254T4 do not apply, see Throttle body (electronic throttle module (ETM)), replacing .
- For B5244T5 2005-, see Throttle body (electronic throttle module (ETM)), replacing (B5244T5 2005-) .
- To clean the throttle unit:
- For -2004, see Throttle body, cleaning
- For 2005- B5xx4T, does not apply to B5244T5, see Throttle body (TB), cleaning
- For 2005- B5244T5, see Throttle body (TB), cleaning (2005- B5244T5) .
- See Engine control module (ECM), replacing
- See Checking wiring and terminals .
Courtesy of VOLVO CARS OF NORTH AMERICA.
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Refer to Adaptation of the throttle unit