Code
B1344
ALFA ROMEO
B — Body
Heated rear window input open circuit
Views:
UK: 3
EN: 6
RU: 4
AI status
Completed
Completed
100%
Causes
- Blown fuse or fusible link for rear window heater
- Open or damaged wiring/harness between control module/relay and heated window connector
- Broken heating element/traces in the rear window glass
- Corroded or poorly seated connector at the window or relay/module
- Faulty switch, relay or control module that supplies the heater input
Symptoms
- Heated rear window does not heat or defog
- Rear window heater indicator lamp may not illuminate
- No audible relay click when heater is selected
- DTC B1344 stored in body/control module
- Intermittent heater operation or complete loss of function
What to check
- Scan vehicle and read stored/pendant codes; note freeze-frame or related codes
- Inspect fuse(s) and fusible links for the rear window heater circuit
- Visually inspect wiring, connectors and the rear window connector for corrosion or damage
- Verify operation of the rear window heater switch and relay (if fitted)
- Measure voltage at the rear window heater connector with switch ON and OFF
- Measure continuity/resistance across the heater grid traces
Signal parameters
- Battery supply voltage at fuse/relay: ~12–14 V with ignition/accessory ON
- Control input to heated rear window: 0 V when OFF, battery voltage when ON (or switched ground depending on design)
- Heated window grid resistance: typically a low value (usually a few ohms); an open circuit will read infinite/OL—consult factory spec for exact value
- Ground continuity for heater circuit: near 0 Ω from connector to chassis ground
- Relay coil/switch control: continuity per manufacturer spec when activated
Diagnostic algorithm
- Connect a scan tool, read/record B1344 and any related codes. Note any freeze-frame data.
- Inspect the rear window heater fuse(s) and replace if blown. Re-check code/operation.
- Visually inspect wiring harnesses, junctions and connectors between the control module/relay and rear window for damage, corrosion, or disconnection.
- Operate the rear window heater switch while measuring voltage at the heater power pin at the rear-window connector. Confirm expected battery/switch voltage appears when activated.
- With power removed, measure resistance across the heater grid terminals at the window connector. A healthy grid reads a low resistance (consult factory spec); an open circuit reads OL/infinite.
- Check continuity from the control module/relay output to the rear-window connector to locate any open segment. Wiggle harnesses while testing to find intermittent opens.
- Verify ground continuity from the heater ground terminal to chassis ground.
- If wiring and connectors are good but grid is open, inspect the glass for visibly broken traces or use a low-voltage continuity/trace tester to locate break(s). Repair or replace glass as required.
- If wiring, connectors and heater grid are good, test/replace relay and verify the switch and control module outputs. Refer to wiring diagrams for module pinouts and perform module-level tests if needed.
- After repair, clear codes, operate the heater through several cycles and confirm the code does not return.
Likely causes
- Blown fuse protecting the heated rear window circuit
- Open/disconnected connector at the rear window or body harness splice
- Damaged/heater grid broken (open circuit) in the glass
- Faulty relay or switch not supplying voltage to the heater input
- Control module internal input failure (less common)
Fault status
Status
Open circuit detected on heated rear window input — no expected input voltage/continuity to the rear window heater. Heater may not operate.
Repair difficulty: Medium
Diagnostic time: 0.5-2 hours
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Code
B1344
FIAT
B — Body
Heated rear window input open circuit
Views:
UK: 2
EN: 5
RU: 4
AI status
Completed
Completed
100%
Causes
- Blown fuse or fusible link for rear window heater
- Open or damaged wiring/harness between control module/relay and heated window connector
- Broken heating element/traces in the rear window glass
- Corroded or poorly seated connector at the window or relay/module
- Faulty switch, relay or control module that supplies the heater input
Symptoms
- Heated rear window does not heat or defog
- Rear window heater indicator lamp may not illuminate
- No audible relay click when heater is selected
- DTC B1344 stored in body/control module
- Intermittent heater operation or complete loss of function
What to check
- Scan vehicle and read stored/pendant codes; note freeze-frame or related codes
- Inspect fuse(s) and fusible links for the rear window heater circuit
- Visually inspect wiring, connectors and the rear window connector for corrosion or damage
- Verify operation of the rear window heater switch and relay (if fitted)
- Measure voltage at the rear window heater connector with switch ON and OFF
- Measure continuity/resistance across the heater grid traces
Signal parameters
- Battery supply voltage at fuse/relay: ~12–14 V with ignition/accessory ON
- Control input to heated rear window: 0 V when OFF, battery voltage when ON (or switched ground depending on design)
- Heated window grid resistance: typically a low value (usually a few ohms); an open circuit will read infinite/OL—consult factory spec for exact value
- Ground continuity for heater circuit: near 0 Ω from connector to chassis ground
- Relay coil/switch control: continuity per manufacturer spec when activated
Diagnostic algorithm
- Connect a scan tool, read/record B1344 and any related codes. Note any freeze-frame data.
- Inspect the rear window heater fuse(s) and replace if blown. Re-check code/operation.
- Visually inspect wiring harnesses, junctions and connectors between the control module/relay and rear window for damage, corrosion, or disconnection.
- Operate the rear window heater switch while measuring voltage at the heater power pin at the rear-window connector. Confirm expected battery/switch voltage appears when activated.
- With power removed, measure resistance across the heater grid terminals at the window connector. A healthy grid reads a low resistance (consult factory spec); an open circuit reads OL/infinite.
- Check continuity from the control module/relay output to the rear-window connector to locate any open segment. Wiggle harnesses while testing to find intermittent opens.
- Verify ground continuity from the heater ground terminal to chassis ground.
- If wiring and connectors are good but grid is open, inspect the glass for visibly broken traces or use a low-voltage continuity/trace tester to locate break(s). Repair or replace glass as required.
- If wiring, connectors and heater grid are good, test/replace relay and verify the switch and control module outputs. Refer to wiring diagrams for module pinouts and perform module-level tests if needed.
- After repair, clear codes, operate the heater through several cycles and confirm the code does not return.
Likely causes
- Blown fuse protecting the heated rear window circuit
- Open/disconnected connector at the rear window or body harness splice
- Damaged/heater grid broken (open circuit) in the glass
- Faulty relay or switch not supplying voltage to the heater input
- Control module internal input failure (less common)
Fault status
Status
Open circuit detected on heated rear window input — no expected input voltage/continuity to the rear window heater. Heater may not operate.
Repair difficulty: Medium
Diagnostic time: 0.5-2 hours
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Code
B1344
HUMMER
B — Body
HeaterDefrost/AC Door Movement Fault
Views:
UK: 3
EN: 10
RU: 4
AI status
Completed
Completed
100%
Causes
- Blown fuse or fusible link for rear window heater
- Open or damaged wiring/harness between control module/relay and heated window connector
- Broken heating element/traces in the rear window glass
- Corroded or poorly seated connector at the window or relay/module
- Faulty switch, relay or control module that supplies the heater input
Symptoms
- Heated rear window does not heat or defog
- Rear window heater indicator lamp may not illuminate
- No audible relay click when heater is selected
- DTC B1344 stored in body/control module
- Intermittent heater operation or complete loss of function
What to check
- Scan vehicle and read stored/pendant codes; note freeze-frame or related codes
- Inspect fuse(s) and fusible links for the rear window heater circuit
- Visually inspect wiring, connectors and the rear window connector for corrosion or damage
- Verify operation of the rear window heater switch and relay (if fitted)
- Measure voltage at the rear window heater connector with switch ON and OFF
- Measure continuity/resistance across the heater grid traces
Signal parameters
- Battery supply voltage at fuse/relay: ~12–14 V with ignition/accessory ON
- Control input to heated rear window: 0 V when OFF, battery voltage when ON (or switched ground depending on design)
- Heated window grid resistance: typically a low value (usually a few ohms); an open circuit will read infinite/OL—consult factory spec for exact value
- Ground continuity for heater circuit: near 0 Ω from connector to chassis ground
- Relay coil/switch control: continuity per manufacturer spec when activated
Diagnostic algorithm
- Connect a scan tool, read/record B1344 and any related codes. Note any freeze-frame data.
- Inspect the rear window heater fuse(s) and replace if blown. Re-check code/operation.
- Visually inspect wiring harnesses, junctions and connectors between the control module/relay and rear window for damage, corrosion, or disconnection.
- Operate the rear window heater switch while measuring voltage at the heater power pin at the rear-window connector. Confirm expected battery/switch voltage appears when activated.
- With power removed, measure resistance across the heater grid terminals at the window connector. A healthy grid reads a low resistance (consult factory spec); an open circuit reads OL/infinite.
- Check continuity from the control module/relay output to the rear-window connector to locate any open segment. Wiggle harnesses while testing to find intermittent opens.
- Verify ground continuity from the heater ground terminal to chassis ground.
- If wiring and connectors are good but grid is open, inspect the glass for visibly broken traces or use a low-voltage continuity/trace tester to locate break(s). Repair or replace glass as required.
- If wiring, connectors and heater grid are good, test/replace relay and verify the switch and control module outputs. Refer to wiring diagrams for module pinouts and perform module-level tests if needed.
- After repair, clear codes, operate the heater through several cycles and confirm the code does not return.
Likely causes
- Blown fuse protecting the heated rear window circuit
- Open/disconnected connector at the rear window or body harness splice
- Damaged/heater grid broken (open circuit) in the glass
- Faulty relay or switch not supplying voltage to the heater input
- Control module internal input failure (less common)
Fault status
Status
Open circuit detected on heated rear window input — no expected input voltage/continuity to the rear window heater. Heater may not operate.
Repair difficulty: Medium
Diagnostic time: 0.5-2 hours
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Code
B1344
Other
B — Body
Heated Backlite Input Circuit Open
Views:
UK: 15
EN: 36
RU: 17
AI status
Completed
Completed
100%
Causes
- Blown fuse or fusible link for rear window heater
- Open or damaged wiring/harness between control module/relay and heated window connector
- Broken heating element/traces in the rear window glass
- Corroded or poorly seated connector at the window or relay/module
- Faulty switch, relay or control module that supplies the heater input
Symptoms
- Heated rear window does not heat or defog
- Rear window heater indicator lamp may not illuminate
- No audible relay click when heater is selected
- DTC B1344 stored in body/control module
- Intermittent heater operation or complete loss of function
What to check
- Scan vehicle and read stored/pendant codes; note freeze-frame or related codes
- Inspect fuse(s) and fusible links for the rear window heater circuit
- Visually inspect wiring, connectors and the rear window connector for corrosion or damage
- Verify operation of the rear window heater switch and relay (if fitted)
- Measure voltage at the rear window heater connector with switch ON and OFF
- Measure continuity/resistance across the heater grid traces
Signal parameters
- Battery supply voltage at fuse/relay: ~12–14 V with ignition/accessory ON
- Control input to heated rear window: 0 V when OFF, battery voltage when ON (or switched ground depending on design)
- Heated window grid resistance: typically a low value (usually a few ohms); an open circuit will read infinite/OL—consult factory spec for exact value
- Ground continuity for heater circuit: near 0 Ω from connector to chassis ground
- Relay coil/switch control: continuity per manufacturer spec when activated
Diagnostic algorithm
- Connect a scan tool, read/record B1344 and any related codes. Note any freeze-frame data.
- Inspect the rear window heater fuse(s) and replace if blown. Re-check code/operation.
- Visually inspect wiring harnesses, junctions and connectors between the control module/relay and rear window for damage, corrosion, or disconnection.
- Operate the rear window heater switch while measuring voltage at the heater power pin at the rear-window connector. Confirm expected battery/switch voltage appears when activated.
- With power removed, measure resistance across the heater grid terminals at the window connector. A healthy grid reads a low resistance (consult factory spec); an open circuit reads OL/infinite.
- Check continuity from the control module/relay output to the rear-window connector to locate any open segment. Wiggle harnesses while testing to find intermittent opens.
- Verify ground continuity from the heater ground terminal to chassis ground.
- If wiring and connectors are good but grid is open, inspect the glass for visibly broken traces or use a low-voltage continuity/trace tester to locate break(s). Repair or replace glass as required.
- If wiring, connectors and heater grid are good, test/replace relay and verify the switch and control module outputs. Refer to wiring diagrams for module pinouts and perform module-level tests if needed.
- After repair, clear codes, operate the heater through several cycles and confirm the code does not return.
Likely causes
- Blown fuse protecting the heated rear window circuit
- Open/disconnected connector at the rear window or body harness splice
- Damaged/heater grid broken (open circuit) in the glass
- Faulty relay or switch not supplying voltage to the heater input
- Control module internal input failure (less common)
Fault status
Status
Open circuit detected on heated rear window input — no expected input voltage/continuity to the rear window heater. Heater may not operate.
Repair difficulty: Medium
Diagnostic time: 0.5-2 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
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0
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