Code
B1354
FIAT
B — Body
Accessory position 1 circuit
AI status
Completed
Completed
100%
Causes
- Open or short in accessory (ACC1) wiring harness
- Faulty ignition switch or key cylinder contacts
- Blown fuse or faulty accessory relay
- Corroded or loose connector at switch, BCM or fusebox
- Short to battery (constant 12V) or short to ground
- Faulty body control module (BCM) or input circuit
Symptoms
- Accessories (radio, infotainment, power windows, cigarette lighter, etc.) do not power in ACC key position
- Intermittent accessory power or accessories working only in ON/START positions
- Possible DTCs related to other body modules losing accessory supply
- Battery drain if ACC circuit stuck on (short to battery)
What to check
- Read and record all stored codes and freeze-frame data from all modules
- Visually inspect fuses, relays, connectors and wiring for ACC circuit
- Verify battery voltage is good (12.4–12.8 V at rest) before testing
- With key in OFF and ACC positions, check for presence/absence of voltage at the ignition switch ACC terminal and ACC1 feed at BCM
- Check continuity between ignition switch ACC terminal and BCM ACC1 input
- Inspect for aftermarket device connections on accessory circuits
Signal parameters
- Expected ACC1 input voltage: ~0 V with key OFF
- Expected ACC1 input voltage: ~11–14 V with key in ACC position
- Rapid voltage transitions when moving key between OFF and ACC; long delays or no change indicate fault
- Resistance/continuity: low ohms between ignition switch ACC terminal and BCM input (exact value depends on wiring length; typically < 5–10 Ω across short sections)
Diagnostic algorithm
- Confirm the code and note when it sets (key position, after jump-start, etc.). Scan for related codes.
- Visually inspect fuses and relays protecting accessory circuits; replace any blown fuse and re-test.
- Locate ignition switch ACC terminal and measure voltage with key OFF and in ACC. If no voltage in ACC, suspect switch or upstream fuse/relay.
- Measure voltage at the BCM ACC1 input connector with key OFF and ACC. If voltage is present at switch but missing at BCM, check wiring/connector between them for open/short.
- Perform continuity and short-to-ground/battery tests on ACC1 wiring with battery disconnected for continuity checks. Repair any open or shorted sections.
- Inspect and repair corroded or loose connectors; reseat and protect connectors. Check grounds related to the accessory circuit.
- If wiring and switch verify OK, swap or bench-test the ignition switch (if possible) or replace it, then re-test.
- If ACC1 still not behaving and input wiring is good, consider BCM input circuit fault. Verify BCM power/ground and consult module pinouts. Replace BCM only after exhaustive wiring/switch elimination and following anti-theft/immobilizer procedures.
- Clear codes and confirm repair by cycling key through OFF/ACC/ON and verifying ACC accessories operate and the code does not return.
Likely causes
- Damaged or disconnected ACC1 wire between ignition switch and BCM
- Worn ignition switch contacts failing to make ACC1 connection
- Blown fuse for accessory feed or bad accessory relay
- Corroded connector or poor ground on accessory circuit
Fault status
Status
Accessory Position 1 Circuit Fault — the vehicle detected an open, short, or incorrect voltage on the ACC1 input. Accessories may not power in the ACC key position.
Repair difficulty: Medium
Diagnostic time: 0.5-2.5 hours
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Repair manuals
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