TN. MFI #25 / DI #8 Load Signal Absent

TN. MFI#25, DI#8

MFI#25 Load signal absent
DI#8 Load signal absent




Fault message conditions:
The fault message is logged if voltage is below 2.5 V for 400 ms.
The measurement is not carried out if fuel shut-off requirements are met - engine speed has been over 2200 rpm and then not dropped below 1100 rpm and the idle switch is on.

Causes of fault:
Break or grounding in the wiring between MFI#25 and DI#8.

Fault symptoms:
None apparent.

TN1




Volvo ST, Test box
- Disconnect the ST in accordance with QA2. QA. Connecting The Volvo Scan Tool (ST)
- Connect the test box to 1CM and check the GND point in accordance with P3-P4. P. Test Box, Signal Description
^ Continue with Checking the load signal to ICM TN2.

TN2




Checking the load signal to ignition control module (ICM)
- Connect the control module to the test box.
- Install the fuse.
- Ignition on.
Connect a voltmeter between DI#8 and DI#20 (GND).
The voltmeter should read 200-500 mV.

If this value is OK
Intermittent fault.
^ Check the connections for loose contacts and intermittent grounding in accordance with NA3. NA. Checking the Wiring

If the reading is approx. 7 V
^ check the wiring between the control modules for breaks in accordance with NA2. NA. Checking the Wiring

If the reading is approx. 0 V
^ check the wiring's resistance to GND TN3.

TN3




Checking the wiring's resistance to GND
- Ignition off.
- Remove the fuse from the battery (740 940 780: #1, 760 960: #31)
- Disconnect both control modules.
Connect an ohmmeter between DI#8 and DI#20 (GND).
The ohmmeter should read infinite resistance.

If this value is OK
^ try using a new control module.

If the reading is incorrect
^ check the wiring between the control modules for grounding In accordance with NA3. NA. Checking the Wiring