Test Point 4 - Temperature Sensor II (Engine)
TEST POINT 4 - Engine temperature sensor (NTC II/Ohms) - Fault code 1_14Possible Causes, Elimination, Remarks
The cylinder head temperature can be read directly in the "Actual value" menu with the system tester 9288.
If no plausible display:
After disconnecting the DME control unit plug, connect an ohmmeter with terminal 45 and terminal 30 by means of test leads.
Display at:
0°C (32° F) = 4.4 - 6.8 Kohms
15-30°C (59-86° F) = 1.4 - 3.6 Kohms
40°C (104° F) = 1.0 - 1.3 Kohms
80°C (176° F) = 250 - 390 Ohms
100°C (212° F) = 160 - 210 Ohms
If the values are not reached, test directly at the engine temperature sensor.
NOTE: The temperature sensor II informs the control unit about the cylinder head temperature. It is responsible for mixture enrichment for cold starting or warming-up.
Break - (infinite resistance):
The DME control unit sets itself to a fixed resistance value permanently stored in the control unit which approximately corresponds to that of an engine at operating temperature. There is no enrichment by the faulty NTC II when the engine is warm (emergency running program). This results in starting problems if the engine is cold (no cold start enrichment).
Short-circuit (0 Ohms):
In cold state, no engine pick-up, too lean, and engine stops. No effect if engine is at operating temperature.
Replacement value is applicable to both types of fault!