Haldex Modular Dolly System (HMDS) -
Air System and Electrical Tests
Haldex Modular Dolly System (HMDS) with Brake
Monitoring System (BMS) for Single Axle Dollies
Installation/Service Guide (L31298W)
PAGE 10
Step 1: Verify Dolly Air System is functioning correctly
- Charge Emergency (IN) gladhand (90 - 120 PSI).
• Service Chambers should release.
• Air Reservoir tank should fill.
• Air bags should inflate after approx. 20 seconds.
• Check and correct any Emergency air leaks.
- Charge Service (IN) gladhand (90 - 120 PSI).
• Service Chambers should apply.
• Check and correct any Service air leaks.
• Release Service (IN) gladhand pressure and brakes should release.
- Release Emergency (IN) gladhand pressure
• Service Chambers should park.
Step 2: Verify Dolly ABS Power
- Apply 12 Volts DC to the Blue ABS Pin #7 on the 7-Way Connector and verify the
external mounted Dolly ABS Lamp goes (ON - OFF). The ABS System is okay.
- If the Dolly ABS Lamp stays (ON) solid, an ABS fault is present. Refer to Intelligent
Trailer Control Module (ITCM) Installation/Service Manual (L31286W) for fault code
details.
- Turn (OFF) Blue ABS Power.
Step 3: Verify Dolly Stoplight Power
- Apply 12 Volts DC to the Stoplight Pin # 4 on the 7-Way Connector and verify the external
mounted Dolly ABS Lamp goes (ON - OFF). The ABS System is okay.
- Verify brake lamps are on when power is applied.
- If the Dolly ABS Lamp stays (ON) solid, an ABS fault is present. Refer to the Intelligent
Trailer Control Module (ITCM) Installation/Service Manual (L31286W) for fault code details.
