Test H

PINPOINT TEST H: INSUFFICIENT, ERRATIC OR NO HEAT

Test H1-H5:

Test H5-H8:

Test H9-H10:

Normal Operation
Under normal operation, the coolant control valve receives battery voltage through circuit 30-FB3 (RD/OG). The coolant control valve is provided a ground through circuit 91S-FB3 (BN/BU) and/or 91S-FB4 (BN/GN) from the Dual Automatic Temperature Control (DATC) module, depending on which side of the heater core that warm coolant is to flow through.

Possible Causes
- An open in circuit 30-FB3 (RD/OG), 91S-FB3 (BN/BU) or 91S-FB4 (BN/GN).
- A short to ground or voltage in circuit 91S-FB3 (BN/BU) or 91S-FB4 (BN/GN).
- Coolant control valve.
- DATC module.
- Thermostat.
- Evaporator discharge air temperature sensor.