Code
B1538
ALFA ROMEO
B — Body
Memory 2 switch circuit short to ground
Views:
UK: 4
EN: 6
RU: 14
AI status
Completed
Completed
100%
Causes
- Damaged wiring harness (insulation chafed, pinched or rubbed through)
- Connector corrosion, bent pins or poor terminal contact
- Switch internal short or failed switch assembly
- Short to ground at a splice or accessory added to the circuit
- Faulty body/control module input (rare)
Symptoms
- Memory 2 preset will not operate or is unresponsive
- Memory/preset error message or indicator in cluster or infotainment
- Intermittent operation of memory functions (works sometimes)
- Related functions (seat/mirror adjustments) may not recall presets
What to check
- Check for additional stored DTCs and freeze frame/fault occurrence data
- Visually inspect switch, wiring harness and connectors for damage, corrosion, or water ingress
- Disconnect the Memory 2 switch connector and check for continuity to ground on the signal pin
- Measure supply and signal voltages at the switch connector with ignition ON
- Wiggle the wiring harness and connectors while monitoring the signal for intermittent shorts
- Inspect for aftermarket accessories or recent repairs that may have altered wiring
Signal parameters
- With ignition ON: supply/reference voltage to switch typically ~9–15 V (vehicle battery rail) depending on design
- Signal line expected: open/high (pulled up) when switch is inactive, low (~0 V) only when switch is commanded to ground (momentary) depending on circuit design
- Continuity: open/infinite when connector disconnected (no short); near 0 Ω indicates direct short to ground
- Typical fault reading: persistent 0 V on signal pin when it should be high or high-impedance
Diagnostic algorithm
- Read all stored codes and note freeze-frame data. Confirm B1538 is current and not historic.
- Locate the Memory 2 switch and trace its wiring back to the body/control module. Inspect connectors for corrosion, bent pins or water.
- With ignition OFF, disconnect the Memory 2 switch connector. Measure resistance between the signal terminal and chassis ground. A near-zero reading indicates a short to ground.
- If short is present, isolate sections of the harness: unplug intermediate connectors or disconnect loads/splices to find where continuity to ground is removed.
- With ignition ON, measure voltage at the switch connector signal terminal. If it reads ~0 V when it should be pulled up, suspect a short. If it toggles when pressing the switch, the switch may be OK.
- Perform a wiggle test: monitor the signal while flexing the harness to reproduce intermittent faults.
- If wiring and connectors check good, bench-test or replace the Memory 2 switch. If replacement resolves the short, reassemble and clear codes.
- If the short remains after switch replacement, inspect/repair wiring (repair or splice replacement), and if necessary replace the body/control module only after wiring is proven good.
- After repair, clear DTCs, cycle ignition and test all memory functions. Verify the code does not return on road/test cycle.
Likely causes
- Shorted conductor between the Memory 2 switch signal and chassis ground due to damaged insulation
- Water ingress or corrosion in the switch connector causing grounding
- Failed Memory 2 switch (internal short)
- Accessory or aftermarket device tied into the circuit creating a direct path to ground
Fault status
Status
B1538 — Memory 2 switch circuit short to ground. The control module detected a low/grounded signal on the Memory 2 switch input when it expected a high or open signal.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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