Kalmar - MSARB Ignition Supply Fault V5 (LCD) Diagnostic

Modified on Fri, 13 Feb at 2:44 PM

1. Fault Overview

When the LCD screen ‘Fault Detected’ menu option displays an Ignition Fault, and the MSB Fault Light DOES NOT illuminate when the ignition is turned to ON (right),

Access the MSB and Screen Faults sub-menu by pressing and holding red fault symbol on screen or via holding the menu button for 3 seconds.

No ignition detected.

The fault conditions will be one of below:

Conditions for setting fault

No Ignition (IGN) supply to MSB ECU.
Faulty wiring harness to MSB ECU.
Interrupted Ignition (IGN) supply to MSB for more than 5 sec while vehicle speed signal (VSS) is received.
Fault in wiring harness to MSB fault light.
MSB fault light.
Internal MSB ECU fault.

NOTE: If the MSB fault light does not light up when ignition is turned ON (either continuously or for the 1 second light test), there is a fault within the wiring to the MSB fault light, or the MSB fault light is faulty.

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

STEP 1: Locate MSB ECU. Unplug the 12-pin Deutsch connector (black).

Using a multi-meter measure across Pin 7 (red) & Pin 6 (black) for constant BAT+ supply voltage.

Measure across Pin 3 (orange) & Pin 6 (black) for ignition (IGN) supply voltage.

Within specifications: Continue to STEP 3 (MSB fault light not illuminating).

Not within specifications: Continue to STEP 2.

STEP 2: Trace wiring harness to vehicle fuse/vehicle connections and repair accordingly.

Verify repair with Full System Test.

STEP 3: With the 12-pin Deutsch connector (black) disconnected, use a bridge wire to bridge Pin 7 (red) to Pin 5 (red/blue) and verify operation of MSB fault light.

Within specifications: The ECU has failed. This scenario is unlikely: repeat all testing again to ensure that it is the ECU that has failed. If all testing has been repeated and testing still indicates that the ECU has failed, replace the ECU.

Verify repair with Full System Test.

Not within specifications: Verify (BAT+) supply and GND to warning light, with bridge wire connected. Repair wiring/replace MSB fault light if not illuminated.

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.