29
Troubleshooting Diagnostic Trouble Codes: Power Supply
6
Power Supply
1st . Blink
Code
Location
Power Supply Tests:
1. Take all measurements at ECU harness connector.
2. Place a load (e.g. an 1157 stop lamp) across battery
or ignition and ground connection, measure 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.
Connector
Pin Power Supply Test
X1
1 Ground
18 Way
3
Ignition
16 Battery
Cab-mount ECU:
Looking into wire
harness connector
3. Check for damaged wiring, damaged or corroded
connectors and connections.
4. Check condition of vehicle battery and associated
components, ground connection good and tight.
5. Check alternator output for excessive noise.
X 4
2nd .
Blink
Code
Diagnostic Trouble
Code Description
Repair Information
1
Battery Voltage Too Low Measure battery voltage under load. Check vehicle battery and associated
components. Check for damaged wiring. Check for damaged or corroded connectors
and connections.
2
Battery Voltage Too
High
Measure battery voltage under load. Ensure that battery voltage is correct for the
ECU. Check vehicle battery and associated components. Check for damaged
wiring. Check for damaged or corroded connectors and connections.
3
Battery Voltage Too
Low During ABS
Measure battery voltage under load. Check vehicle battery and associated
components. Check for damaged wiring. Check for damaged or corroded connectors
and connections.
4
Battery Voltage Open
Circuit
Measure battery voltage under load. Check condition of fuse. Check vehicle battery
and associated components. Check for damaged wiring. Check for damaged or
corroded connectors and connections.
5
Ignition Voltage Too
Low
Measure ignition voltage under load. Check vehicle battery and associated
components. Check for damaged wiring. Check for damaged or corroded connectors
and connections. Check condition of fuse.
6
Ignition Voltage Too
High
Measure ignition voltage. Ensure that ignition voltage is correct for the ECU. Check
vehicle battery and associated components. Check for damaged wiring. Check for
damaged or corroded connectors and connections.
7
Ignition Voltage Too
Low During ABS
Measure ignition voltage under load. Check vehicle battery and associated
components. Check for damaged wiring. Check for damaged or corroded connectors
and connections.
8
Input Voltage Has
Excessive Noise
(Temporary)
Check alternator output for excessive noise. Check for other devices causing
excessive noise.
9
Input Voltage Has
Excessive Noise
Check alternator output for excessive noise. Check for other devices causing
excessive noise.
