Checking components and wiring
Check the cable between central electronic module (HEM) terminal #8 and the signal cable for the flame sensor. Check for a short-circuit to ground.
HINT: It is difficult to differentiate between the ground lead for the flame sensor and the signal cable. Take readings on one cable at a time to check for a plausible value on either of them.
Replace the flame sensor if no fault is found in the cable.
Remedy as necessary.
Other information
- See Connecting the breakout box
- See Signal specification
- To access or replace the engine coolant temperature sensor. For cars manufactured up to w38 2001 inclusive, see Overheat protection thermostat / flame sensor / engine coolant temperature sensor, replacing
- For cars manufactured from w39 2001 inclusive, see Replacing the overheat protection thermostat, the flame sensor and the engine coolant temperature sensor .
- See Checking wiring and terminals
- Continue
Refer to Verification
- Check the central electronic module (HEM) connector. Check for contact resistance and oxidation
- Check the cable between central electronic module (HEM) terminal #8 and the signal terminal for the flame sensor. Check for an intermittent short-circuit to ground.
Remedy as necessary.
Other information
- Continue
Refer to Verification