Code
P1652
DAEWOO
P — Powertrain
Ignition sw fault
Views:
UK: 3
EN: 10
RU: 5
AI status
Completed
Completed
100%
Causes
- Worn or faulty ignition switch (internal contacts)
- Damaged wiring or poor connector contact to ignition switch
- Corroded or loose ground
- Blown fuse or faulty ignition/starter relay
- Low or unstable battery voltage
- Faulty Body/BCM, PCM or related module interpreting the switch signal
Symptoms
- No-crank or intermittent crank condition
- Vehicle fails to start or starts intermittently
- Accessories (radio, dash lights) do not function in ACC/ON positions
- Dash lights flicker or behave unpredictably with key movement
- Stalling or loss of power when key position changes
- Starter engages unexpectedly or remains engaged
What to check
- Retrieve freeze frame and all stored DTCs with a scan tool and record key position info
- Visually inspect ignition switch connector and harness for damage, corrosion or pin backout
- Check battery voltage at rest and during crank (should be ~12.4–12.8 V at rest, >9.5 V under load depending on vehicle)
- Inspect fuses and starter/ignition relays for continuity and correct operation
- Wiggle test the ignition key while monitoring behavior of accessories and engine
- Check for related immobilizer or BCM codes and warning lights
Signal parameters
- ACC position: battery voltage (~12 V) present on ACC output terminal
- ON position: battery voltage present on IGN/IGN1 circuit terminals
- START position: START terminal should show battery voltage while starter engaged; IGN outputs may remain powered
- Voltage drop on any ignition circuit under load should be minimal (
- Continuity/ohms across switch contacts: near 0 ohms when closed, open/infinite when open
- Intermittent or fluctuating voltage when key is held between positions indicates internal switch wear or poor connection
Diagnostic algorithm
- Confirm the code and capture freeze frame; note key position when code set.
- Check battery charge and condition. Charging system should be within spec before further testing.
- Visually inspect ignition switch connector, wiring, and grounds for damage or corrosion. Repair as needed.
- With a DVOM, backprobe ignition switch terminals and verify expected voltages in OFF/ACC/ON/START positions. Have an assistant turn the key.
- Check fuses and relays for ignition/starter circuits. Swap with a known-good relay if suspect.
- Perform a wiggle test of the steering column while monitoring voltages and customer-reported symptoms to reproduce intermittent faults.
- If voltages/circuit behavior are abnormal, isolate wiring to locate open, short or high-resistance point. Repair wiring or connector.
- If wiring and fuses are good but switch outputs are intermittent or incorrect, remove and bench-test or replace the ignition switch assembly.
- If ignition switch and wiring check good, inspect BCM/ECM input circuits and CAN communication; consult wiring diagram and test module inputs/grounds.
- Clear codes, perform functional test and road test to verify repair. Re-scan to confirm code does not return.
Likely causes
- Internal failure of the ignition switch assembly (most common)
- Broken/frayed wires in the steering column harness (pinched by tilt column)
- Oxidation/corrosion at the ignition switch connector or terminal
- Weak battery causing voltage drop during crank
- Faulty starter relay or associated fuse
- Faulty BCM/ECM input circuit or CAN communication fault
Fault status
Status
Ignition switch circuit fault detected — verify ignition switch, wiring, fuses/relays and related module inputs.
Repair difficulty: Medium
Diagnostic time: 1.0 - 3.0 hours
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