SRS Warning Light Comes On, But Fault Code(S) Do Not Display
WARNING: This page is about a different car, the 1996 Volvo 850. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition off and connect Volvo Scan Tool to DLC. Turn on switch on adapter box. Check communication with SRS system. If communication with SRS system is okay, fault is probably in D+ supply to SRS sensor module. Go to step 2). If there is no communication with SRS system the fault is probably in battery voltage supply to SRS sensor module. Go to step 3).
- Turn ignition off. Remove connector from generator D+ connecting pin. Turn ignition on and check voltage between ground and D+ connecting pin. Voltage should be between 0.7 and 2.0 volts. Start engine and remeasure voltage. Voltage should be approximately 14.5 volts. If both readings are okay, D+ supply is okay and there is probably an open circuit between generator and SRS sensor module. If either voltage is not as specified, replace generator.
- Turn ignition off and disconnect negative battery cable. Ensure connector to generator D+ connecting pin is connected. Remove SRS sensor module connector. Turn ignition on. Check voltage between ground and sensor module connector terminal No. 12. Voltage should be between 0.7 volts and 2.0 volts. Start engine. Check voltage between ground and sensor module connector terminal No. 12. Voltage should be approximately 14.5 volts. If both readings are okay, replace sensor module. If either voltage is not as specified, check wiring harness between sensor module connector terminal No. 12 and generator connector D+ for open-circuit.