1. Fault Overview
When the ‘P’ and ‘D’ LEDs flash alongside a beep every 30 seconds from the LED module’s buzzer, and the MSB Fault Light remains constantly illuminated when the ignition is turned to ON,
The fault conditions will be one of below:
Conditions for setting fault
- The door is detected as OPEN while the vehicle is travelling over 10km/h for over 15 seconds.
- The door is not detected as OPEN with 5 occurrences of the vehicle park brake being applied and the operator off the seat.
NOTE: A full inspection of the door switch(es) and the door circuit wiring harness must be performed. In dual control vehicles, both door circuits MUST be checked independently. Check that the vehicle’s interior lights activate from the vehicle door switch(es).
NOTE: Diagnose/repair any OEM door wiring circuit faults prior to undertaking the following troubleshooting process. It is highly recommended that the door switch(es) be replaced if the weatherproof membrane is damaged.
NOTE: See integration notes for vehicle specific door connections.
After completing diagnosis and rectifying any faults, a full system test must then be performed and documented on the Systems Confirmation Test – MAX-SAFE Anti-Rollaway Brake System test sheet prior to returning the vehicle to service.
2. Diagnostic Procedure
Ensure that ALL testing is conducted in a controlled, safe, and legal manner. It is recommended that an observer watches the status of the system whilst testing is being conducted.
STEP 1: Clear the fault by isolating the vehicle power supply at the batteries for at least 1 second. Reconnect the power supply to the vehicle. Open the door. The ‘D’ LED should illuminate. Close the door, and the ‘D’ LED should turn off. Repeat this test 15 times.
Within specifications: Visually inspect door switches, connections. Replace any damaged/corroded or worn components
Verify repair with Full System Test.
Not within specifications: Continue to STEP 2
STEP 2: Visually inspect door switches, connections. Replace any damaged/corroded or worn components.
Locate MSB ECU. Disconnect the Black connector (12-Way) at the ECU. Locate the green/white wire (Pin 7). Verify wiring harness back to MSB door connection, checking shorted/damaged wiring harnesses. Repairing as required.
NOTE: An intermittent short to the ground on the door circuit can also cause a door fault. On dual control vehicles both the left and right-hand door switches, and the wiring circuits, need to be inspected.
Verify repair with Full System Test.
3. Full System Test
Undertake a full system test of the MAX-SAFE Brake System and document the results on the test sheet found within the document Systems Confirmation Test – MAX-SAFE Anti-Rollaway Brake System prior to returning the vehicle to service.
Should the testing outlined within the Systems Confirmation Test fail for any reason, the system must be thoroughly inspected, diagnosed and repaired, as per the relevant Diagnostic Process document, prior to the vehicle being returned to service.
Integration Notes
1. The Iveco Acco PRE E6 uses a dedicated door signal connector (a single pin connector, black in colour). The MAX-SAFE Brake green/white wire connects to this connector, located at the body builder’s connector, on floor level under the centre lower dashboard panel. The voltage at this connector when door is closed should be over 12 volts. With door open the voltage should be under 1 volt.
2. The Iveco Acco E6 connects to both the left and right-hand circuits with a blocking diode connected at the rear cabin controller connector.
3. In Isuzu single control vehicles, the door input from the driver-side door switch has a diode fitted in circuit, close to the door switch.
4. Mercedes Benz vehicles have the door circuit connected behind the driver-side seat, at the body control module.
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