5.
Read "DTC Status" parameter.
The Chassis Acceleration Sensor (CAS) consists of a piezoelectric vibration pick up which detects vertical acceleration of the vehicle. The sensor signal is used by the ECM to determine the degree of vertical movement of the car, for example, on a bumpy road. Since this may also cause uneven engine running, the ECM uses the signal to distinguish the phenomenon from actual misfiring.
ECM sets DTC P1309 if the ECM detects signal voltage higher than the possible range of a properly operating CAS.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Signal check,High | ● Contact resistance in connectors ● Open or short to battery in signal circuit ● Open in ground circuit ● Faulty CAS ● Faulty ECM |
Enable Conditions | ||
Threshold Value | ● CAS signal ＞ 3.5 V | |
Diagnostic Time | ||
MIL ON Condition | ● 3 Driving Cycles |
Acceleration (G) | -5 | -3 | -1 | 0 | 1 | 3 | 5 |
Output Voltage (V) (Approx.) | 0.26~1.74 | 1.16~1.44 | 2.05~2.15 | 2.5 | 2.85~2.95 | 3.56~3.84 | 4.26~4.74 |
Connect scantool to Data Link Connector(DLC).
IG "ON"＆ ENG "OFF".
Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC's information from the DTCs menu.
Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions noted in the DTC detecting condition.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
History fault : DTC occurred but has been cleared.
Present fault : DTC is occurring at present time.
▶ Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or was repaired and ECM 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.
Many malfunctions in the electrical system are caused by poor harness and terminals. Faults canalso be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination,deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and go to "Verification of vehicle Repair" procedure
▶ Go to "Signal Circuit inspection" procedure.
Signal circuit voltage check.
Ignition "OFF".
Disconnect CAsensor connector.
Ignition "ON" & Engine "OFF".
Measure voltage between terminal "3" of sensor harness connector and chassis ground.
Specification : Approx. 5V
Is the measured voltage within specifications?
▶ Go to "Ground circuit inspection" procedure.
▶ Check for open or short in signal harness. Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Check for short in harness.
Ignition "OFF".
Disconnect CS sensor connector and ECM connector.
Measure resistance between terminal "1" and "3"of the sensor harness connector .
Specification : infinite
Is the measured resistance within specifications?
▶ Go to "Ground circuit inspection" procedure.
▶ Check for short to power in signal harness. Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Ignition "OFF".
Disconnect CA sensor connector.
Measure voltage between terminal 1 of harness connector and chassis ground.
Measure voltage between terminal 1 and 2 of harness connector.
Specification : "A" - "B" = Below 200mV
Is the measured resistance within specifications?
▶ Go to "Component inspection" procedure.
▶ Check for open in ground harness. Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Check CAS.
Substitute with a known - good CAS and check for proper operation.
Is the signal normal?
▶ Replace CAS and go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known - good ECM and check for proper operation.If the problem is corrected, replace ECM and go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
Clear the DTCs and Operate the vehicle within DTC Enable conditions in General information.
Are any DTCs present ?
▶ Go to the applicable troubleshooting procedure.
▶ System is performing to specification at this time.
