GRID HEATER RELAY

OPERATION
The Engine Control Module (ECM) operates the heating element through the intake manifold air heater relay. Refer to the Diagnostic Procedures section for an electrical operation and complete description of the intake heater, including pre-heat and post-heat cycles.

REMOVAL
The intake manifold air heater relay (5) is located in the engine compartment. It attached to a bracket. This bracket is attached to the right battery tray (3). The mounting bracket and relay is replaced as an assembly.
1. Disconnect both negative battery cables at both batteries.
2. Disconnect relay trigger wires (4) at relays. Note position of wiring before removing.
3. Remove nuts (2) at cable connectors and disconnect cables (1) from mounting studs. Note position of cables before removing.
4. Remove two relay mounting bracket screws (6) and remove relay assembly.

INSTALLATION
The intake manifold air heater relay (5) is located in the engine compartment. It attached to a bracket. This bracket is attached to the right battery tray (3). The mounting bracket and relay is replaced as an assembly.
1. Position relay and install two relay mounting bracket screws (6).
2. Position cables (1) to mounting studs and install nuts (2).
3. Connect relay trigger wires (4) at relays.
4. Connect both negative battery cables to both batteries.