P1600

P1600
Power Supply (Ignition on) - too Low
Power Supply - Below Lower Limit

P1601
Power Supply (Ignition on) - too High
Power Supply - Upper limit exceeded

Function
The Engine Control Module (ECM), i.e. the RAM cells, are supplied with voltage by terminal 30. In case that the voltage is too high or too low, a proper recording of faults cannot be assured.

Diagnostic conditions
Battery voltage is higher than 16 Volt - Voltage limit exceeded
Battery voltage is below 10 Volt and at least 1 minute after starting the engine - Below voltage limit

NOTE: When a fault is recorded in memory, the idle air control adaptation is blocked.





Wiring Diagram.

Diagnostic procedure.





DTC P1600.





DTC P16O1.

Check wiring terminal 30 for transition resistance.
1. Remove connector X 4/2
2. Connect voltmeter on cavity side to pin 1 (plus) and ground.

- Specified value: battery voltage
- If meter does not read battery voltage, check wiring from connector X 4/2, pin 1 to central electric fuse/relay panel, connector D 15 for continuity. Check connector for corrosion.

3. Reconnect connector X 4/2.
4. Remove ECM connector.
5. Connect voltmeter to pin 26 (plus) and ground.

- Specified value: battery voltage.
- If meter does not read battery voltage, check wiring from ECM connector, pin 26 to connector X 4/2 on pin side, pin 1 for continuity. - Check connector for corrosion.