B1293

Code

ALFA ROMEO B — Body

Battery supply relay circuit open

Brand: ALFA ROMEO

Type: B — Body

Views: UK: 6 EN: 5 RU: 6

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Page language: EN

No power to systems that are switched through the battery supply relay (depending on vehicle architecture)
Starter, fuel pump, or ECUs may not receive battery feed; vehicle may not start or accessory power is lost
Battery warning or electrical system warnings on dash
Intermittent electrical faults or modules failing to wake/sleep
DTC stored and possibly inability to clear until circuit fixed

Read stored codes and freeze frame with a scan tool; note related codes and voltage status
Visually inspect relay, relay socket and related connectors for corrosion, burning or damage
Check relevant fuse(s) and fusible links for continuity
Measure battery voltage (engine off and running) to ensure adequate supply before tests
Check wiring continuity between battery, fuse, relay supply terminal and control module output
Measure control/coil voltage at the relay with ignition ON and when commanded

Battery voltage at relay supply terminal: ~11.5–14.5 V (should be near battery voltage with ignition on)
Relay coil/control signal: 0 V (not energized) or battery voltage (~12 V) when the module commands the relay closed
Coil resistance (typical automotive relay): ~50–150 ohms (refer to vehicle-specific spec)
Continuity from battery positive to relay supply terminal: near 0 ohms (no open circuit)
Control module output pin resistance to coil: low when commanded (check against factory spec)

Confirm the code and note any additional DTCs; record battery voltage.
Inspect externally visible wiring, relay socket and fuses for damage, corrosion or loose connections.
Verify fuse/fusible link continuity that feeds the relay; replace if blown and re-test.
With ignition OFF, remove relay and measure coil resistance. Compare to specification or typical 50–150 ohms.
Reinstall relay and with ignition ON, measure supply terminal voltage and coil/control pin voltage while commanding the circuit with a scan tool or ignition sequence.
If relay does not energize then supply voltage is missing or control signal not present — trace continuity from battery positive through fuse to relay supply; repair any open circuit.
If supply and control signal are present but relay does not switch, replace the relay and re-test.
If control signal is absent, test continuity and voltage at control module pin; check module ground and refer to wiring diagram. Repair harness or connector as needed.
After repairs, clear codes and perform functional test/road test to confirm the fault does not return.
If wiring and relay are good but control output fails, consider module diagnostics or replacement per manufacturer procedures.

Defective or stuck-open battery supply relay
Open or intermittent wiring between battery, fuse and relay (damaged harness, chafing, connector)
Blown fuse or fusible link supplying the relay
Corroded/loose relay connector or poor ground
Faulty control module driver (less common)

⚠️ Status

Battery supply relay circuit open — open circuit detected in the battery feed or control circuit to the relay, preventing relay activation.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2 hours

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