Symptom:
SYSTEM UNDERVOLTAGE
When Monitored and Set Condition:
SYSTEM UNDERVOLTAGE
When Monitored:
Ignition on. The CAB monitors the Fused Ignition Switch Output
circuit voltage above 10 km/h (6 mph) every 7 milliseconds for proper system voltage.
Set Condition:
If the voltage is below 9.5 volts, the Diagnostic Trouble Code (DTC) is set.
POSSIBLE CAUSES
BATTERY VOLTAGE LOW
INTERMITTENT DTC
FUSED IGNITION SWITCH OUTPUT CIRCUIT HIGH RESISTANCE
GROUND CIRCUIT OPEN
CAB - INTERNAL FAULT
TEST
ACTION
APPLICABILITY
1
Turn the ignition on.
With the DRBIII
t
, erase DTC’s.
Turn the ignition off.
Turn the ignition on.
Start the engine.
Drive the vehicle above 16 km/h (10 mph) for at least 20 seconds.
Stop the vehicle
With the DRBIII
t
, read DTC’s.
Does the DRBIII
t
display System Undervoltage DTC?
All
Yes
→
No
→
2
Engine Running.
Measure the battery voltage.
Is the battery voltage below 10 volts?
All
Yes
→
Refer to appropriate service information for charging system
testing and repair.
Perform ABS VERIFICATION TEST - VER 1.
No
→
3
Turn the ignition off.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the ground circuits.
Is the resistance below 1.0 ohm?
All
Yes
→
No
→
Repair the Ground circuit for an open.
Perform ABS VERIFICATION TEST - VER 1.
59
BRAKES (CAB)
