Cold Mixture Heater (CMH) System
- Start engine. On Corolla & Pickup, ensure coolant temperature is less than 109°F (43°C). On Tercel, ensure coolant temperature is less than 118°F (48°C).
- On all models, using a voltmeter, ensure voltage is present between CMH positive terminal and body ground. See POSITIVE TERMINAL WIRE COLORS table for correct wire color application. Ensure voltmeter probe is inserted from rear of connector. See Fig 1.POSITIVE TERMINAL WIRE COLORS
Application Wire Colors Corolla White/Red Pickup Blue/Yellow Tercel White/Red - Warm engine to above 131°F (55°C). Ensure voltage is not present. If a problem is not found, system is okay. If system fails to operate as specified, perform following component tests.