Toyota 4-Runner 1985 Repair Manual page 169

Ohmmeter
EMISSION CONTROL SYSTEMS (CARB.) - Auxiliary Systems
EC-69
Ohmmeter
(Large)
Voltmeter
~ -)
Type A
Ohmmeter
EC4205
3. CHECK CMH WITH WARM ENGINE
(a) Warm up the engine to above 55°C (131°F).
(b) Check that there is no voltage.
IF NO PROBLEM IS FOUND WITH THIS INSPECTION, THE
SYSTEM IS OKAY; OTHERWISE INSPECT EACH PART
A03087
INSPECTION OF THERMO SWITCH (1)
(See page EC-23)
INSPECTION OF CMH
MEASURE RESISTANCE
(a) Unplug the wiring connector.
(b) Using an ohmmeter, measure the resistance between
the positive
(+)
terminal and intake manifold.
Resistance at 20°C (68°F):
Type A (NO) 0.35 - 1.0
n
Type B (TDK) 0.5 - 2.0
n
(c) Plug in the wiring connector.
INSPECTION OF CMH RELAY
1. INSPECT RELAY CONTINUITY
Check that there is continuity between terminals 1 and 2.
Check that there is no continuity between terminals 3 and
4.
Relay location: Right fender apron
2. INSPECT RELAY OPERATION
Check the continuity between terminals
3
and 4 with bat-
tery voltage applied between terminals 1 and 2.