Code
P1697
MINI
P — Powertrain
Engine control (EC) relay, control circuit - low input
Views:
UK: 2
EN: 7
RU: 1
AI status
Completed
Completed
100%
Causes
- Blown/loose fuse for EC relay coil or ECM power circuit
- Faulty EC (engine control/ECM) or relay module
- Open or shorted wiring in relay control circuit (short to ground)
- Bad relay (stuck open, coil open)
- Corroded/loose connector pins at relay, fusebox, BCM or ECM
- Faulty ignition switch or body control module (BCM) driver
Symptoms
- No-crank/ no-start or intermittent cranking problems (if ECM not powered)
- Engine stalls or dies shortly after starting
- No communication with ECM on a scan tool (ECM asleep or unpowered)
- MIL (malfunction indicator lamp) or stored power-relay DTCs
- Loss of engine management functions, limp-home mode or reduced performance
What to check
- Retrieve DTCs and freeze frame with a scan tool; check for related codes (voltage, communication, relay)
- Check battery voltage and battery terminal integrity (key ON: ~12.0–12.6 V; engine running: ~13.5–14.8 V)
- Visually inspect relay, fuse(s), wiring harness and connectors for damage, corrosion or looseness
- Locate EC relay and identify coil control and supply pins using wiring diagram
- Measure voltage at relay supply and control terminals with ignition ON/START
- Check continuity and resistance from relay control terminal to BCM/ECM driver and to ground
Signal parameters
- Ignition ON (Key ON, Engine OFF): relay coil supply = battery voltage (~11.5–13.0 V)
- Control input when driver energizes relay = battery voltage (approx. 11.5–14.5 V)
- Fault condition: control input seen as low/near 0 V (typically
- Relay coil resistance (typical range) = normally tens to a few hundred ohms; check OEM spec
- If ECM is powered, CAN/diagnostic bus should be active; no ECM comms may indicate lost supply
Diagnostic algorithm
- Confirm DTC: Clear codes, cycle ignition and try to reproduce P1697 using scan tool; note if code is stored or current.
- Battery & fuses: Verify battery state and tight terminals; check all fuses related to EC relay, ECM power and BCM.
- Visual inspection: Inspect relay socket, relay, fusebox and wiring harness for corrosion, melted plastic or water.
- Measure relay supply: With ignition ON, measure battery voltage at the relay supply terminal. If missing, trace feed back to fuse/ignition switch/BCM.
- Measure relay control: With appropriate pins identified, measure voltage at relay control terminal while crank/ON. If control is low (
- Relay swap/test: Swap in a known-good relay of same type or bench-test suspect relay; verify coil continuity and switching.
- Wiring check: Perform continuity and resistance checks between relay control terminal and the controlling module pin (BCM/ECM) with connectors disconnected. Check for short to ground/short to voltage.
- Check ECM/BCM driver: If wiring and relay check OK but control still low, test the driver output at the BCM/ECM per factory procedures (may require module bench test or oscilloscope).
- Repair and verify: Repair wiring, replace relay/fuse or faulty module as indicated. Clear codes and confirm system operates normally over multiple ignition cycles.
- If intermittent: Wiggle-test harnesses, apply moisture if safe and directed by service manual, and use data-logging to capture transient low-input events.
Likely causes
- Failed EC relay
- Fuse for relay/EC power open
- Grounded or open relay control wire between relay and BCM/ECM
- Corroded connector at fuse/relay block or ECM
- Weak battery or poor battery terminal connection
Fault status
Status
Engine control (EC) relay control circuit — low input detected. The control line to the engine control relay is reporting a low voltage when a high/12V signal is expected. May cause ECM power loss or no communication.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email