Relay Control Module Test

WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

The relay control module is part of the under-hood fuse/relay box, and it contains these relays:

PGM-FI main relay 1
Ignition coil relay
PGM-FI subrelay
ETCS control relay
Horn relay

If any of these relays fail the test, replace the under-hood fuse/relay box.

Do the battery terminal disconnection procedure (see USING THE GR8 BATTERY DIAGNOSTIC STATION ), then disconnect under-hood fuse/relay box connectors C (2P), E (14P), and H (9P).
NOTE: All connector views are wire side of female terminals.

Fig 1: Identifying Under-Hood Fuse/Relay Box Connectors C (2P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Identifying Under-Hood Fuse/Relay Box Connectors E (14P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 3: Identifying Under-Hood Fuse/Relay Box Connectors H (9P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Connect battery power to terminal C2.
PGM-FI main relay 1:
- Connect terminal E5 to body ground. There should be battery voltage between terminal H1 and body ground.
- Disconnect terminal E5 from the body ground. There should be no voltage between terminal H1 and the body ground.
Ignition coil relay:
- Connect terminal E5 to body ground. There should be battery voltage between terminal H6 and body ground.
- Disconnect terminal E5 from the body ground. There should be no voltage between terminal H6 and the body ground.
PGM-FI subrelay
- Connect terminals E5 and E13 to body ground. There should be battery voltage between terminal H9 and body ground.
- Disconnect terminal E5 from the body ground. There should be no voltage between terminal H9 and the body ground.
ETCS control relay:
- Connect terminals E5 and E14 to body ground. There should be battery voltage between terminal H7 and body ground.
- Disconnect terminal E5 from the body ground. There should be no voltage between terminal H7 and body ground.
Connect battery power to terminal H3.
Horn relay:
- Connect terminal E4 to body ground. There should be battery voltage between terminal H4 and body ground, and between terminal H5 and body ground.
- Disconnect terminal E4 from the body ground. There should be no voltage between terminal H4 and body ground, and between terminal H5 and body ground.