Code
B1338
ALFA ROMEO
B — Body
Right rear door open circuit short to ground
Views:
UK: 4
EN: 7
RU: 4
AI status
Completed
Completed
100%
Causes
- Damaged wiring harness in door hinge area (pinched, chafed, cut)
- Corroded or bent connector pins at the door jamb or latch
- Short between the door switch signal wire and vehicle ground
- Failed door ajar/micro switch inside latch or door module
- Water intrusion causing conductive path to ground
- Faulty Body Control Module (BCM) or door control unit
Symptoms
- Right rear door ajar message or icon illuminated
- Interior or door courtesy light stays on or behaves erratically
- Central locking/remote may not lock/unlock right rear door
- Possible battery drain with vehicle parked
- DTC present in diagnostics and related features disabled
What to check
- Use a scan tool: read DTC, freeze frame and live data for right rear door input
- Visually inspect wiring through the right rear door hinge boot and door jamb
- Inspect and unplug door connector; check for corrosion, bent pins, water
- Backprobe the signal pin at the door and at the BCM while opening/closing the door
- Measure continuity between the signal wire and chassis ground with harness disconnected
- Perform a wiggle test on harness while monitoring live input to reproduce fault
Signal parameters
- Signal type: digital door-ajar input (switch to ground or to battery depending on design)
- Expected voltage (common): ≈ 0 V (ground) when switch is closed to ground; ≈ battery voltage (9–14 V) or pulled-up logic voltage when open
- Expected resistance: closed circuit typically
- Typical current: very low (mA range) — short will cause abnormal low-voltage or continuous ground
- Note: exact polarity (ground-switched vs. supply-switched) varies by model—verify with wiring diagram before replacing parts
Diagnostic algorithm
- Connect a diagnostic scanner, confirm B1338 and any related codes, record freeze-frame/live data behavior.
- Visually inspect the right rear door area: latch, switch, wiring harness through the hinge boot, and connectors for damage or water.
- With battery connected, backprobe the door signal wire at the door connector and at the BCM/door module. Observe voltage with door open and closed to determine normal vs shorted behavior.
- Unplug the door connector. With the harness disconnected from the switch, measure continuity between the signal wire and chassis ground. A short will show near-zero ohms. If short present in harness, repair wiring.
- Perform a wiggle/stress test on the harness through the hinge while watching the live signal; this identifies intermittent shorts from flexing.
- Inspect connector pins for grounding on the shell or adjacent pins. Repair corroded pins, reseal boots and connectors.
- If wiring and connector appear good, bench-test or replace the door latch/switch and retest.
- If problem remains after known-good switch and repaired wiring, inspect/replace BCM or door module input fuse/relay and retest according to OEM procedures.
- After repair, clear fault codes, verify proper door status on scanner and test drive/operate door to confirm DTC does not return.
Likely causes
- Wire chafed at hinge leading to intermittent short to body metal
- Connector terminal backed out/shorted to ground due to corrosion
- Damaged door latch switch or actuator with internal short
- Water-damaged wiring or connector creating a grounded path
- BCM input damaged (less common)
Fault status
Status
Right rear door open circuit: short to ground detected on the door-ajar input. The control module is reading the circuit as grounded when it should be open. Inspect wiring, connector, and door latch/switch.
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
Code
B1338
FIAT
B — Body
Right rear door open circuit short to ground
Views:
UK: 2
EN: 5
RU: 3
AI status
Completed
Completed
100%
Causes
- Damaged wiring harness in door hinge area (pinched, chafed, cut)
- Corroded or bent connector pins at the door jamb or latch
- Short between the door switch signal wire and vehicle ground
- Failed door ajar/micro switch inside latch or door module
- Water intrusion causing conductive path to ground
- Faulty Body Control Module (BCM) or door control unit
Symptoms
- Right rear door ajar message or icon illuminated
- Interior or door courtesy light stays on or behaves erratically
- Central locking/remote may not lock/unlock right rear door
- Possible battery drain with vehicle parked
- DTC present in diagnostics and related features disabled
What to check
- Use a scan tool: read DTC, freeze frame and live data for right rear door input
- Visually inspect wiring through the right rear door hinge boot and door jamb
- Inspect and unplug door connector; check for corrosion, bent pins, water
- Backprobe the signal pin at the door and at the BCM while opening/closing the door
- Measure continuity between the signal wire and chassis ground with harness disconnected
- Perform a wiggle test on harness while monitoring live input to reproduce fault
Signal parameters
- Signal type: digital door-ajar input (switch to ground or to battery depending on design)
- Expected voltage (common): ≈ 0 V (ground) when switch is closed to ground; ≈ battery voltage (9–14 V) or pulled-up logic voltage when open
- Expected resistance: closed circuit typically
- Typical current: very low (mA range) — short will cause abnormal low-voltage or continuous ground
- Note: exact polarity (ground-switched vs. supply-switched) varies by model—verify with wiring diagram before replacing parts
Diagnostic algorithm
- Connect a diagnostic scanner, confirm B1338 and any related codes, record freeze-frame/live data behavior.
- Visually inspect the right rear door area: latch, switch, wiring harness through the hinge boot, and connectors for damage or water.
- With battery connected, backprobe the door signal wire at the door connector and at the BCM/door module. Observe voltage with door open and closed to determine normal vs shorted behavior.
- Unplug the door connector. With the harness disconnected from the switch, measure continuity between the signal wire and chassis ground. A short will show near-zero ohms. If short present in harness, repair wiring.
- Perform a wiggle/stress test on the harness through the hinge while watching the live signal; this identifies intermittent shorts from flexing.
- Inspect connector pins for grounding on the shell or adjacent pins. Repair corroded pins, reseal boots and connectors.
- If wiring and connector appear good, bench-test or replace the door latch/switch and retest.
- If problem remains after known-good switch and repaired wiring, inspect/replace BCM or door module input fuse/relay and retest according to OEM procedures.
- After repair, clear fault codes, verify proper door status on scanner and test drive/operate door to confirm DTC does not return.
Likely causes
- Wire chafed at hinge leading to intermittent short to body metal
- Connector terminal backed out/shorted to ground due to corrosion
- Damaged door latch switch or actuator with internal short
- Water-damaged wiring or connector creating a grounded path
- BCM input damaged (less common)
Fault status
Status
Right rear door open circuit: short to ground detected on the door-ajar input. The control module is reading the circuit as grounded when it should be open. Inspect wiring, connector, and door latch/switch.
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
Code
B1338
Other
B — Body
Door Ajar RR Circuit Short To Ground
Views:
UK: 15
EN: 37
RU: 18
AI status
Completed
Completed
100%
Causes
- Damaged wiring harness in door hinge area (pinched, chafed, cut)
- Corroded or bent connector pins at the door jamb or latch
- Short between the door switch signal wire and vehicle ground
- Failed door ajar/micro switch inside latch or door module
- Water intrusion causing conductive path to ground
- Faulty Body Control Module (BCM) or door control unit
Symptoms
- Right rear door ajar message or icon illuminated
- Interior or door courtesy light stays on or behaves erratically
- Central locking/remote may not lock/unlock right rear door
- Possible battery drain with vehicle parked
- DTC present in diagnostics and related features disabled
What to check
- Use a scan tool: read DTC, freeze frame and live data for right rear door input
- Visually inspect wiring through the right rear door hinge boot and door jamb
- Inspect and unplug door connector; check for corrosion, bent pins, water
- Backprobe the signal pin at the door and at the BCM while opening/closing the door
- Measure continuity between the signal wire and chassis ground with harness disconnected
- Perform a wiggle test on harness while monitoring live input to reproduce fault
Signal parameters
- Signal type: digital door-ajar input (switch to ground or to battery depending on design)
- Expected voltage (common): ≈ 0 V (ground) when switch is closed to ground; ≈ battery voltage (9–14 V) or pulled-up logic voltage when open
- Expected resistance: closed circuit typically
- Typical current: very low (mA range) — short will cause abnormal low-voltage or continuous ground
- Note: exact polarity (ground-switched vs. supply-switched) varies by model—verify with wiring diagram before replacing parts
Diagnostic algorithm
- Connect a diagnostic scanner, confirm B1338 and any related codes, record freeze-frame/live data behavior.
- Visually inspect the right rear door area: latch, switch, wiring harness through the hinge boot, and connectors for damage or water.
- With battery connected, backprobe the door signal wire at the door connector and at the BCM/door module. Observe voltage with door open and closed to determine normal vs shorted behavior.
- Unplug the door connector. With the harness disconnected from the switch, measure continuity between the signal wire and chassis ground. A short will show near-zero ohms. If short present in harness, repair wiring.
- Perform a wiggle/stress test on the harness through the hinge while watching the live signal; this identifies intermittent shorts from flexing.
- Inspect connector pins for grounding on the shell or adjacent pins. Repair corroded pins, reseal boots and connectors.
- If wiring and connector appear good, bench-test or replace the door latch/switch and retest.
- If problem remains after known-good switch and repaired wiring, inspect/replace BCM or door module input fuse/relay and retest according to OEM procedures.
- After repair, clear fault codes, verify proper door status on scanner and test drive/operate door to confirm DTC does not return.
Likely causes
- Wire chafed at hinge leading to intermittent short to body metal
- Connector terminal backed out/shorted to ground due to corrosion
- Damaged door latch switch or actuator with internal short
- Water-damaged wiring or connector creating a grounded path
- BCM input damaged (less common)
Fault status
Status
Right rear door open circuit: short to ground detected on the door-ajar input. The control module is reading the circuit as grounded when it should be open. Inspect wiring, connector, and door latch/switch.
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