V90 L6-2.9L VIN 96 B6304S (1998)
Malfunction Indicator Lamp: Description and Operation
The Malfunction Indicator Lamp (MIL) is activated if the engine management systems malfunction. Malfunctions can cause engine running problems
and result in the engine failing to maintain required emission levels.
In some markets where an On-Board Diagnostics II(OBD II) system is a statutory requirement, the Transmission Control Module (TCM) can also
activate the MIL. The TCM sends a request to the Engine Control Module (ECM) to activate the MIL if an emission-related transmission malfunction
occurs. (The Motronic 4.4 ECM posts a Diagnostic Trouble Code (DTC) when the transmission sends a MIL request.)
Refer to the illustration for the OBD II DTC equivalents of the Volvo DTCs. The MIL lights when the system posts the following automatic transmission
DTCs:
AT-121 Shift solenoid S1, short circuit to ground
AT-122 Shift solenoid S1, fault on the solenoid circuit
AT-123 System pressure solenoid 5th, short circuit to supply
AT-132 TCM, 5th amplifier short circuit
AT-213 Throttle Position (TP) sensor signal, signal too high
AT-221 Shift solenoid S2, short circuit to ground
AT-222 Shift solenoid S2, fault in the solenoid circuit
AT-223 TP sensor signal, signal
AT-232 Vehicle Speed Signal (VSS), signal missing
AT-311 Transmission speed sensor, signal missing
AT-313 Gear-shift position sensor, incorrect signal
AT-321 Gear 1, incorrect ratio
AT-322 Gear 2, incorrect ratio
AT-323 Gear 3, incorrect ratio
