Dtc B1520 / B1521 / B1522: Temperature / Blower Speed / Air Flow Selector Malfunction - Suzuki SX4 Service Manual
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Also See for SX4:
- Owner's manual (47 pages) ,
- Owner's manual (16 pages) ,
- Owner's manual (278 pages)
Table of Contents
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DTC Troubleshooting
Step
1
Was "Air Conditioning System Check" performed?
2
DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ignition switch to ON position and check DTC.
Is DTC B1512 detected together?
3
Visual Check
Check if there is any obstruction in operating range of
actuator linkage and if actuator linkage operates smoothly.
Is it in good condition?
4
Wire harness check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from air flow control actuator and
HVAC control module.
3) Check for proper connection to actuator motor drive
circuit terminals of air flow control actuator and HVAC
control module connectors.
4) If OK, check that actuator motor drive circuit of air flow
control actuator is as follows.
• Wiring harness resistance of each actuator motor
drive circuit is less than 3 Ω
• Insulation resistance of each actuator motor drive
circuit is infinity between air flow control actuator
connector and vehicle body ground
• Circuit voltage of each actuator motor drive circuit is 0
– 1 V with ignition switch turned ON
Are they in good condition?
5
Wire harness check
Check position sensor circuit of temperature control actuator
for condition referring to Step 2 of "DTC B1512: Air flow
Control Actuator (Position Sensor) and/or Its Circuit
Malfunction: Automatic Type".
Is it in good condition?
6
Air Flow control actuator check
1) Check air flow control actuator for performance referring
to "Air Flow Control Actuator and Its Circuit Inspection:
Automatic Type".
Is it in good condition?
DTC B1520 / B1521 / B1522: Temperature / Blower Speed / Air Flow Selector Malfunction
DTC Detecting Condition and Trouble Area
DTC Detecting Condition
When internal malfunction is detected in the
HVAC control module.
Action
• Temperature selector included in HVAC control module (DTC
B1520)
• Blower speed selector included in HVAC control module (DTC
B1521)
• Air flow selector included in HVAC control module (DTC B1522)
Air Conditioning System: Automatic Type 7B-65
Yes
Go to Step 2.
Go to "DTC B1512: Air
flow Control Actuator
(Position Sensor) and/or
Its Circuit Malfunction:
Automatic Type".
Go to Step 4.
Go to Step 5.
Go to Step 6.
Substitute a known-
good HVAC control
module and recheck.
Trouble Area
No
Go to "Air Conditioning
System Check:
Automatic Type".
Go to Step 3.
Obstruction in operating
range of actuator
linkage, actuator linkage
faulty and/or internal
fault of HVAC unit.
Actuator motor drive
circuit(s) is open, short
or high resistance.
Repair or replace.
Replace air flow control
actuator.
S7RW0A7224017
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Table of Contents
Troubleshooting
Need help?
Do you have a question about the SX4 and is the answer not in the manual?
Questions and answers
Adjust throttle motor
The idle speed on a Suzuki SX4 should be controlled by the Idle Air Control Valve (IACV) rather than adjusting the idle screw on the throttle body, as the screw is factory set. Before using compressed air in the idle-air-bypass passages, the IACV should be removed to prevent damage to its delicate mechanism. If there is an issue with idle speed, checking the IACV function and referring to the SX4 service manual is recommended.
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I have an issue of crank but not starting When I scan it brought this codeU0100 Which means no communication thou crank sensor wire was cut off but it was fix back What could be wrong and what could be the solution,
My heater stopped working the blower **** is good, control unit ?
Possible issues with the heater in a Suzuki SX4 if the blower is working but the heater is not include:
1. Incorrect Temperature Output
- Temperature control cable broken or bent (non-A/C and manual A/C) → Check the temperature control cable.
- Temperature selector faulty (non-A/C and manual A/C) → Check the temperature selector.
- Incorrect installation of the temperature control cable (non-A/C and manual A/C) → Check and adjust the position as necessary.
- Temperature control door assembly broken → Repair the temperature control door assembly.
- Air ducts clogged → Repair air ducts.
- Heater core leaked or clogged → Replace the heater core.
- Heater hoses leaked or clogged → Replace heater hoses.
- Thermostat faulty → Check the thermostat.
- Temperature control actuator faulty (auto A/C) → Check the temperature control actuator.
- HVAC control module faulty (auto A/C) → Check the HVAC control module.
- Wiring or grounding faulty (auto A/C) → Repair as necessary.
2. Other Possible Causes
- Air flow control cable broken or bent → Check the air flow control cable.
Checking and addressing these components should help identify and resolve the heater issue.
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دلایل بالا رفتن مصرف بنزین در مدل اتومات
increasing revs when changing gears
The Suzuki SX4 may have increasing revs when changing gears due to its drive-by-wire system and the difference in final drive ratios between the manual (4.41) and automatic (2.81) transmissions. This difference causes high cruising RPMs in the manual version and sluggishness in the automatic. Additionally, if the revs climb while going uphill, it may be due to the transmission downshifting or kicking out of overdrive. Other possible causes include low transmission fluid, abuse, or a faulty transmission design.
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