C1274
DTC C1274 LONGITUDINAL G SENSOR OPEN/SHORTCOMPONENT LOCATION:
GENERAL DESCRIPTION
The 4WD vehicle measures the G-sensor signal to solve for 4WD vehicle unique problems. For example all 4 wheels are locked early on a low-friction road or control response is delayed when road friction coefficients vary. The HECU uses a filtered signal, as a supplementary value, to determine the road friction coefficient. This value is used for the accurate calculations of assumed vehicle speed, or precise division of control starting points.
DTC DESCRIPTION
The HECU monitors the G-sensor voltage continuously, and sets this code if the voltage is either higher than the permissible normal value approximately 4.5 V or lower than the value approximately 0.6V for more than 250ms.
DTC DETECTING CONDITION
SCHEMATIC DIAGRAM:
MONITOR SCANTOOL DATA
1. Connect scan tool to Data Link Connector (DLC)
2. Ignition "ON" Engine "OFF".
3. Monitor the "G Sensor" parameter on the scan tool.
4. Is parameter displayed within specifications?
YES
Fault is intermittent caused by poor connection in G sensor harness and/or HECU's connector or was repaired and HECU memory was not cleared.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure,
NO
Go to "Terminal and Connector Inspection" procedure.
TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness (es) and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES
Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
Go to "Power Circuit Inspection" procedure.
POWER CIRCUIT INSPECTION
OPEN OR SHORT CHECK
1. Ignition "ON" Engine "OFF".
2. Measure voltage between power terminal of the G sensor harness connector and chassis ground.
Specification Approximately 5V
3. Is the measured value within specifications?
YES
Go to "Ground Circuit Inspection" procedure.
NO
Repair open or short in power circuit between the G sensor harness connector and HECU harness connector and then, go to "Verification of Vehicle Repair" procedure.
If there is no problem in Power circuit, Substitute with a known-good HECU and check for proper operation.
If problem is corrected, replace HECU and then go to "Verification of Vehicle Repair" procedure.
GROUND CIRCUIT INSPECTION
OPEN OR SHORT CHECK
1. Ignition "OFF" Engine "OFF".
2. Disconnect the G sensor connector.
3. Measure resistance between ground terminal of the G sensor harness connector and chassis ground.
Specification Approximately below 1 Ohms
4. Is the measured value within specifications?
YES
Go to "Signal Circuit Inspection" procedure.
NO
Repair open or short in ground circuit between the G sensor harness connector and HECU harness connector and then, go to "Verification of Vehicle Repair" procedure.
SIGNAL CIRCUIT INSPECTION
OPEN OR SHORT CHECK
1. Ignition "ON" Engine "OFF".
2. Measure voltage between G sensor signal terminal of the HECU harness connector and chassis ground.
Specification Approximately 2.5V
3. Is the measured value within specifications?
YES
Substitute with a known-good HECU and check for proper operation.
If problem is corrected, replace HECU and then go to "Verification of Vehicle Repair" procedure.
NO
Repair open or short in signal circuit between the G sensor harness connector and HECU harness connector, and then go to "Verification of Vehicle Repair" procedure.
If there is no problem in Signal circuit, Go to "Component Inspection" procedure.
COMPONENT INSPECTION
OPEN OR SHORT CHECK
1. Ignition "ON" Engine "OFF".
2. Measure voltage between signal terminal of the G sensor harness connector and chassis ground.
Specification Approximately 2.5V
3. Is the measured value within specifications?
YES
Fault is intermittent caused by poor connection in G sensor harness and/or HECU's connector.
Go to "Verification of Vehicle Repair" procedure.
NO
Substitute with a known-good G sensor and check for proper operation.
If problem is corrected, replace G sensor and then go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode
2. Using a scan tool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information.
4. Using a scan tool, Check DTC present.
5. Are any DTCs present
YES
Go to the applicable troubleshooting procedure.
NO
System performing to specification at this time.