CL 500 (215.375) V8-5.0L (113.960) (2000)
/v8-5.0l_(113.960)/Page-1424002.png)
The engine shown is engine 166
B11/4
Coolant temperature sensor
G3/1
O2 sensor downstream of TWC (low emission EURO3/D4)
G3/2
O2 sensor upstream of TWC
K1/6
Electronics relay
L5
Crankshaft position sensor
N3/5
ECM control unit (up to 08/01)
N3/18
ECM control unit with throttle valve actuator (as of 09/01)
The purpose of the O2 sensor heater is to rapidly heat up the O2 sensors to their operating temperature while preventing damage to the sensor ceramic as
a result of controlled heating power.
The sensor heater is actuated by the engine control unit through ground. The performance of the sensor heater at operating temperature amounts to:
18 w on Engine 104, 111, 119, 120 and 112, 113 with ME2.0
12 w on Engine 166 .
7 W on Engine 137, engine 111EVO and 112, 113 with ME 2.8 as of 06/00
The voltage for the sensor heater is supplied by the:
- Overvoltage protection relay model 124, 202 up to 7/96
- Relay module, Model 170, Model 210 up to 2/97
- Base module, Model 129, 140
- Fuse and relay module, model 202 as of 8/96, model 210 as of 3/97, model 163 designation F1
- Electronics relay, Model 166
- Right fuse and relay module (K40/7), Model 215, 220
- Right fuse and relay module (K40/4), Model 230
- Front SAM control unit with fuse and relay module Model 203, 209, 211
The current in the cold state is increased by approximately 4 times. At coolant temperatures below approx. 20 °C and at high engine speeds, the sensor
heater is switched off.
Engine 112, 113
The sensor heaters for the left and right O2 sensors are connected in parallel in the ME-SFI control unit.
Engine 119
The sensor heaters for the left and right O2 sensors are connected in parallel.
Engine 120
The sensor heaters for the left and right O2 sensors are assigned to the respective engine control unit.
Engine 137
Each sensor heater has its own, short-circuit proof output stage in the engine control unit with diagnosis. As a protection for the ceramic, the sensor
