Code
C1438
LAND ROVER
C — Chassis
Rear accelerometer - battery short circuit
Views:
UK: 7
EN: 9
RU: 13
AI status
Completed
Completed
100%
Causes
- Short circuit between sensor supply/signal wire and battery positive (B+).
- Internal fault in the rear accelerometer (internal short).
- Damaged, chafed or pinched wiring harness or connector causing insulation failure.
- Corroded, loose or contaminated connector pins at the accelerometer or control module.
- Failed ABS/ESP or body control module that powers or monitors the sensor.
- Water ingress or contamination at the sensor or connector.
Symptoms
- Stability control / DSC / ABS warning lamp illuminated.
- Chassis or suspension warning messages (loss of traction/stability features).
- Fault code C1438 stored in ABS/ESP/chassis module.
- Intermittent or permanent degradation of electronic stability functions.
- Possible limp-home mode or reduced vehicle dynamic control.
What to check
- Retrieve freeze-frame and live data with a diagnostic scanner; confirm C1438 is current or historic.
- Visual inspection of rear accelerometer connector and harness for damage, corrosion, or water.
- Check for related DTCs in ABS, air suspension, and body control modules.
- Inspect fuses and relays that supply the sensor circuit.
- Backprobe sensor connector and measure supply, signal and ground voltages with ignition ON (reference vehicle wiring diagram).
- Perform resistance/continuity checks from sensor wires to battery positive and to ground (energized and de-energized as appropriate).
Signal parameters
- Supply voltage: typically battery voltage (approx. 12 V) or regulated 5 V depending on vehicle — consult vehicle wiring diagram.
- Signal output: many accelerometers are analog (e.g., ~2.5 V at 0 g) or digital/CAN — verify type before measuring.
- Short condition: sensor signal or supply reading near battery positive (close to B+) indicates short to B+.
- Expected continuity: low resistance between sensor ground and vehicle chassis ground; supply pin should not be shorted to battery positive with ignition OFF unless designed as direct B+ feed.
- Always verify parameters against vehicle-specific service data before drawing conclusions.
Diagnostic algorithm
- Read and record all stored DTCs and live sensor data from ABS/ESP and related modules.
- Visually inspect the rear accelerometer, connector, and harness routing for chafing, impact damage, or corrosion.
- With ignition OFF, disconnect the accelerometer connector and check resistance between the sensor supply/signal pins and battery positive. A very low resistance indicates a short to B+.
- With ignition ON (engine not running), backprobe the sensor connector to measure supply voltage, signal voltage and ground reference. Compare to vehicle-specific expected values.
- If supply is held at B+ at the connector with sensor unplugged, trace wiring toward the module looking for shorts, taps or aftermarket connections. Isolate sections by disconnecting intermediate connectors and re-checking.
- If the short disappears when the sensor is unplugged and supply at the module is correct, suspect a faulty sensor. If the short persists with the sensor disconnected, suspect wiring or module fault.
- Inspect for water ingress or corrosion; clean and dry connectors, repair damaged wiring with proper splices and sealed connectors.
- If wiring and connectors are good, test or swap with a known-good rear accelerometer (or replace sensor) per OEM procedure.
- After repair or replacement, clear codes, perform an ignition cycle and run a road test or system self-test to confirm the fault does not return.
- If fault remains after sensor and wiring repair, test/replace the controlling module only after confirming module is the root cause and following module programming/replacement procedures.
Likely causes
- Wiring harness damage near suspension or chassis where cable flexes.
- Connector corrosion at the accelerometer (common on underbody sensors).
- Sensor internal short due to water ingress or age.
- Short to battery from previous repair or aftermarket accessory tapping into harness.
Fault status
Status
Rear accelerometer circuit fault: short to battery detected. The monitored sensor supply or signal is being held at battery voltage (B+), causing invalid accelerometer readings and triggering chassis/stability control fault C1438.
Repair difficulty: Medium
Diagnostic time: 1.0 - 2.5 hours
Similar codes
HTML Workshop Manuals AI manual library for LAND ROVER Click to show available manuals 1
LAND ROVER 2015 Discovery Sport HSE
HTML ManualWorkshop Manuals
Repair manuals for LAND ROVER
3
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop Manual199,00 UAH
Land Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)
Workshop Manual199,00 UAH
Land Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)
Workshop Manual199,00 UAH
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