User's Manual

29
Connector Pin Power Supply Test
X1
18 Way
1 Ground
2 Ignition
16 Battery
Troubleshooting Diagnostic Trouble Codes (DTCs): Power Supply
6 Power Supply
1st. Blink
Code
Location
Power Supply Tests:
1. Take all measurements at the ECU harness
connector.
2. Place a load (e.g. an 1157 stop lamp) across the
battery or ignition and ground connection, measure
the ignition and battery voltage with the load. Ignition
to Ground should measure between 9 to 17 VDC.
Battery to Ground should also measure between 9 to
17 VDC.
Cab-mount ECU:
Looking into wire
harness connector
3. Check for damaged wiring, damaged or corroded
connectors and connections.
4. Check the condition of the vehicle battery and
associated components, verify that the ground
connection is good and tightened.
5. Check the alternator output for excessive noise.
X4
2nd.
Blink
Code
Diagnostic Trouble
Code Description
Repair Information
1
Battery Voltage Too
Low
Measure the battery voltage under load. Check the vehicle battery and associated
components. Check for damaged wiring. Check for damaged or corroded connectors
and connections.
2
Battery Voltage Too
High
Measure the battery voltage under load. Ensure that battery voltage is correct
for the Electronic Control Unit (ECU). Check the vehicle battery and associated
components. Check for damaged wiring. Check for damaged or corroded connectors
and connections.