Ohms Measurements

CAUTION: When measuring ohms disconnect the ECU from the harness plug and never turn the ignition key on. It is possible that failure to follow these steps will result in damage to the ECU.

Grounds:

Deceleration Micro Switch:

Coolant Temperature Sensor:

- Terminal 7 is for MY 1988 and later California versions.

ISC Valve:

Throttle Switch:

** If throttle is opened reading should go to infinity. Does not apply for micro switch version on 84-87 190E.

Electro-hydraulic Actuator:

Air Flow Sensor:

*** Disconnect Altitude sensor before making any reading on the Air Flow sensor as the Altitude sensor will affect the readings.

1. Deceleration micro switch is not applicable prior to MY 1987 190E 2.3. Instead the signal on this terminal is a start signal and is tested in the volts section.

1. Flap on air flow sensor closed or air flow sensor plate at rest position. Resistance increases as flap or plate opens.

2. Flap on air flow sensor opened to maximum or air flow plate deflected to maximum.