B1359

Code

Other B — Body

Ignition Run/Acc Circuit Failure

Brand: Other

Type: B — Body

Views: UK: 26 EN: 42 RU: 32

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Page language: EN

Causes

Blown or corroded fuse in the RUN/ACC feed
Faulty ignition switch or key cylinder electrical contacts
Failed RUN/ACC relay or related power relay
Open, short to ground, or short to battery voltage in wiring or connectors
Poor or corroded ground at modules or chassis
Faulty body control module (BCM) or other module that monitors/controls the circuit

Symptoms

Accessories (radio, cigarette lighter, power windows) do not work in ACC or RUN positions
Dash cluster or instrument lights may be dim or not illuminate when key is ON
Engine cranks but will not start if ECM/PCM not getting RUN power
Intermittent loss of accessory power or modules waking up sporadically
Multiple interior electrical faults or erratic module behavior
Possible battery drain or parasitic draw if circuit shorted

What to check

Confirm DTC B1359 present with a scan tool and record freeze-frame data
Check battery resting voltage (12.4–12.8 V typical) and charging system voltage with engine running (13.5–14.8 V typical)
Visually inspect fuses, fuse holders and RUN/ACC relay; replace suspect items
Backprobe or meter-check for presence of battery voltage on ACC and RUN circuit pins with ignition OFF, ACC, and ON
Inspect connector pins for corrosion, damage or pushed-out terminals at ignition switch, BCM and fused junctions
Check chassis and module grounds for corrosion, tightness and continuity to negative battery

Signal parameters

Battery resting voltage: ~12.4–12.8 V
Charging voltage (engine running): ~13.5–14.8 V
ACC terminal voltage: ~battery voltage when key in ACC
RUN/IGN terminal voltage: ~battery voltage when key in ON (RUN)
Ground continuity: near 0 ohms to chassis (typically
Open-circuit continuity: battery feed to module/fuse should show near 0 Ω (allowance for connector/resistor values per wiring diagram)

Diagnostic algorithm

Retrieve B1359 with a scan tool, note freeze-frame and any related codes. Clear codes and attempt to re-create the fault to confirm persistence.
Verify battery condition and charging system. Weak battery can cause false undervoltage detections—repair charging/battery issues first.
Inspect fuses and relays in the RUN/ACC feed. Replace suspect fuses/relays and re-scan.
With key OFF/ACC/ON, backprobe the ignition switch ACC and IGN/RUN terminals and measure voltage. Confirm expected voltages in each key position.
Trace the RUN/ACC feed from the ignition switch through fuse boxes, relays and connectors to the BCM/ECM. Check for continuity and shorts to ground or battery using a multimeter.
Inspect and clean grounds for modules involved in the circuit. Tighten ground straps and re-test.
Inspect wiring visually for chafing, pinched sections, rodent damage, or aftermarket taps. Wiggle harnesses while observing voltage and module behavior to find intermittent faults.
If wiring and passive components check good, test the ignition switch for intermittent contact or bench-test/replace if suspect.
Verify BCM/module power outputs and inputs per service manual. If module inputs are correct but outputs wrong, consider module replacement or reprogramming following manufacturer procedure.
After repairs, clear codes, perform functional checks of ACC and RUN functions and road/test to confirm fault not recurring.

Likely causes

Blown fuse or faulty RUN/ACC relay
Ignition switch internal contact failure
Open or short in the RUN/ACC wiring harness or connector corrosion
Poor ground or battery/charging system voltage problem
Faulty BCM or a module reporting the circuit incorrectly

Fault status

⚠️ Status

Ignition Run/Accessory circuit failure — the control module detected missing or incorrect voltage on the RUN/ACC feed. Accessories or engine control may not receive required power.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0 - 2.5 hours