Code
P1691
MINI
P — Powertrain
Electronic throttle control monitor level 2/3 - motorised throttle control engine speed limitation error
AI status
Completed
Completed
100%
Causes
- Faulty motorised throttle body (actuator/motor)
- Throttle position sensor(s) failure or out-of-range correlation
- Damaged wiring or poor connector contact at the throttle body
- Low battery voltage or poor ground affecting actuator drive
- Blown fuse or relay in throttle/ECU supply circuit
- ECU/software fault or corrupted throttle adaptation
Symptoms
- Check Engine Light (MIL) illuminated
- Reduced engine power / limp-home mode (engine speed limited)
- Delayed, erratic or no throttle response to accelerator input
- RPM held at reduced limit or unstable idle
- Possible stored multiple throttle-related DTCs
What to check
- Read all stored DTCs and freeze-frame data with a capable scanner (include module-specific MINI/diagnostic tool)
- Check battery voltage and charging system under load (expect ~12–14.5 V)
- Inspect throttle body connector and wiring for damage, corrosion, or loose pins
- Check fuses and relays for throttle/ECU power circuits
- Monitor live data: accelerator pedal position, throttle position(s) 1 & 2, commanded throttle, actuator status and any error flags
- Attempt a throttle actuator output test / drive using OEM diagnostic functions (watch plate movement and current draw)
Signal parameters
- Battery supply to throttle actuator: nominally ~12 V (varies by model); should be stable during command
- Throttle position sensors: two independent outputs; typical 0.5–4.5 V range each, with a fixed relationship/correlation
- Actuator drive signal: PWM or H-bridge drive from ECU (frequency varies by design, often tens-to-hundreds Hz)
- Commanded throttle position vs actual feedback should follow within manufacturer tolerance
- No intermittent open/shorts on power/ground/CAN wiring under wiggle test
Diagnostic algorithm
- Read codes and freeze-frame; note when fault occurred and any related codes.
- Check battery voltage and condition. Charge or load-test if low; retest with good battery.
- Visually inspect throttle body connector and wiring harness for damage, chafing, water intrusion or corrosion. Repair any problems.
- Verify fuses/relays supplying the throttle/ECU. Replace suspect items and retest.
- Using a scanner, monitor accelerator pedal position, TPS1 and TPS2, commanded throttle and actual throttle feedback while key on / engine running. Look for mismatch, stuck values, or dropout.
- Perform a wiggle test on wiring while monitoring signals to reveal intermittent faults.
- Perform OEM bi-directional actuator test (command throttle open/close) and observe plate movement and current draw; note if motor fails to move or draws excessive current.
- If sensors show out-of-range values, measure TPS voltages with a DVOM/oscilloscope to confirm signal integrity and correct voltage ranges.
- Attempt throttle adaptation/learn per factory procedure after repairs and clear codes; retest for reoccurrence on road or roller.
- If wiring, power and adaptation pass but fault persists, replace the throttle body assembly. Re-check and, if necessary, update ECU software or replace ECU per manufacturer guidance.
- If intermittent or unexplained faults continue, inspect network communications (CAN) and related modules; consult OEM bulletins/technical data.
Likely causes
- Throttle body actuator (motor) failure or internal fault
- Correlated TPS signals out of range or not matching (sensor correlation fault)
- Wiring harness damage or pin corrosion at throttle connector
- Battery/charging system voltage drop during actuator command
- Failed throttle body (replace or rebuild) after confirming wiring and power
Fault status
Status
Electronic throttle control monitor level 2/3 — motorised throttle control engine speed limitation. Throttle actuator/sensor or associated wiring/ECU fault detected; engine speed limiting (limp) was applied.
Repair difficulty: Medium
Diagnostic time: 1.5-3 hours
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