Engine Coolant Temperature (ECT) Gauge Test

CAUTION: Turn ignition off before gauge pointer reaches "H" mark, or ECT gauge may be damaged.

Check fuse No. 1 (10-amp), located in underdash fuse/relay box in left kick panel. Turn ignition off. Disconnect Yellow/Green wire from ECT sending unit. Sending unit is located in middle of engine.
Using a jumper wire, ground ECT sending unit Yellow/Green wire. If ECT gauge pointer does not move, check for poor connections or open in Yellow/Green wire between ECT sending unit and ECT gauge. If wire is okay, replace ECT gauge. If ECT gauge pointer moves, check ECT sending unit. See ENGINE COOLANT TEMPERATURE (ECT) SENDING UNIT TEST.