DTC P0234:00 [PCM (SKYACTIV-D)]

Description	Small-type turbocharger area control system: Overboost
Detection condition	Determination condition	• As the result of comparing the actual boost pressure with the target boost pressure, the actual boost pressure exceeds the specification higher than the target boost pressure for a continuous 7 s.
	Preconditions	• All of the following conditions are met when diesel particulate filter regeneration control is stopped during boost control feedback ― Fuel injection amount: 20 mm³/st or more ― Engine speed: 1,400—10,000 rpm or more ― Battery voltage: 11 V or more ― Engine torque down request by G-vectoring control plus (GVC PLUS): Less than 25 N·m {2.5 kgf·m, 18 ft·lbf} ― G-vectoring control plus (GVC PLUS) operation duration time: Less than 3 s ― Barometric pressure: 70—255 kPa{0.72—2.60 kgf/cm², 11.0—36.9 psi} ― Ambient temperature: -10—255 °C {14—491 °F} ― The following DTCs are not detected • ECT sensor: P0117:00, P0118:00 • IAT sensor No.1: P0112:00, P0113:00 • MAP sensor: P0106:00, P0107:00, P0108:00 • BARO sensor: P2228:00, P2229:00 • MAF sensor: P0102:00, P0103:00 • Exhaust gas temperature sensor No.3: P242C:00, P242D:00 • Exhaust gas pressure sensor No.2: P2454:00, P2455:00 • CKP sensor: P0336:00, P0337:00 • Intake shutter valve position sensor: P0122:00, P0123:00 • Intake shutter valve control system: P1589:00, P2101:00, P2118:00 • Actuator position sensor (turbocharger with variable turbine geometry): P2564:00, P2565:00 • Exhaust gas pressure sensor No.1: P0471:00, P0472:00, P0473:00 • Exhaust gas temperature sensor No.1: P0545:00, P0546:00 • Constant voltage power supply control system: P0642:00, P0643:00 • MAP sensor/BARO sensor: P0105:00 • Exhaust gas pressure sensor No.1: P0470:00 • Turbocharger solenoid valve range/performance problem: P2263:00
	Drive cycle	• 2
	Self-test type	• CMDTC self test
	Sensor/unit used	• MAP sensor
Fail-safe	• Not applicable
Vehicle status when dtcs are output	• Not applicable
Possible cause	• PCM input signal error ― MAP sensor signal ― Input signal part connector or terminal malfunction ― Input signal part-related wiring harness malfunction • Turbocharger solenoid valve malfunction • Actuator position sensor (turbocharger with variable turbine geometry) malfunction • Turbocharger actuator malfunction • Turbocharger malfunction • PCM malfunction

• The PCM diagnoses the small-type turbo system performance by comparing the target boost pressure with the actual.

• The PCM uses the manifold absolute pressure sensor to monitor the intake manifold pressure during boost control as the actual boost pressure.

• When the monitoring conditions are met during boost control, the PCM compares the target boost pressure with the actual. If the actual boost pressure is higher than the specification for the target boost pressure, the PCM determines an excess boost malfunction.

• The PCM performs diagnosis when each of the preconditions during drive cycle is met. If a malfunction is detected, the malfunction detection counter begins counting up. If it is normal, the counter begins counting down.

The value of the malfunction detection counter is maintained while the preconditions are not being met. If the cumulative value of the malfunction detection counter exceeds the threshold during the first drive cycle, a malfunction is determined and a pending code is stored.

• If the PCM determines that the malfunction recurs from the next drive cycle and thereafter, it stores a DTC.

1. Display PID MAP_DSD and MAP using the M-MDS.

2. Start the engine and warm it up.

3. Accelerate in 2nd gear to 40 km/h.

4. Accelerate in 2nd gear from 40 km/h to 55 km/h taking 5 s or more.

5. Verify that the difference of more than 30 kPa does not continue for 3 s or more between the MAP_DSD and MAP while accelerating.

Item (definition)	Reference
MAP	• (See PID/DATA MONITOR TABLE [PCM (SKYACTIV-D)].)
MAP_DSD
TURBO_POS_ACT

Item (definition)	Reference
TURBO_POS_DSD	• (See SIMULATION TABLE [PCM (SKYACTIV-D)].)

Step	Inspection	Results	Action
1	PURPOSE: VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY • Verify related Service Bulletins, on-line repair information, or Service Information availability. • Is any related Information available?	Yes	Perform repair or diagnosis according to the available information. • If the vehicle is not repaired, go to the next step.
1		No	Go to the next step.
2	PURPOSE: VERIFY DTC CAUSING FREEZE FRAME DATA • Is DTC P0234:00 causing the freeze frame data?	Yes	Go to the next step.
2		No	Inspect the DTC causing the freeze frame data. (See DTC TABLE [PCM (SKYACTIV-D)].)
3	PURPOSE: RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION • Record the freeze frame data/snapshot data. Note • Recording can be facilitated using the screen capture function of the PC.	—	Go to the next step.
4	PURPOSE: VERIFY OTHER RELATED DTCs • Switch the ignition OFF, and then switch it ON (engine off). • Display the DTCs using the M-MDS. (See DTC INSPECTION.) • Has any DTC other than P0234:00 been stored?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-D)].)
4		No	Go to the next step.
5	PURPOSE: VERIFY MAP SENSOR INPUT SIGNAL • Start the engine and warm it up. • Display the following PIDs using the M-MDS. (See DTC INSPECTION.) ― MAP_DSD ― MAP • Are the monitoring values normal?	Yes	Go to Troubleshooting Diagnostic Procedure to perform the procedure from step 1.
5		No	Go to the next step.
6	PURPOSE: INSPECT WIRING HARNESSES AND CONNECTORS FOR RELATED-SENSOR • Display the following PIDs using the M-MDS. (See DTC INSPECTION.) ― MAP_DSD ― MAP • When the PCM and MAP sensor connector are shaken, does the PID value include a PID item which has changed?	Yes	Inspect the related wiring harnesses and connectors. • Repair or replace the malfunctioning location. Go to the troubleshooting procedure to perform the procedure from repair completion verification.
6		No	Go to Troubleshooting Diagnostic Procedure to perform the procedure from step 1.
7	PURPOSE: DETERMINE IF MALFUNCTION IS CAUSED BY ACTUATOR POSITION SENSOR MALFUNCTION • Inspect the actuator position sensor. (See ACTUATOR POSITION SENSOR (TURBOCHARGER WITH VARIABLE TURBINE GEOMETRY) INSPECTION [SKYACTIV-D 1.8].) • Is the actuator position sensor normal?	Yes	Go to Troubleshooting Diagnostic Procedure to perform the procedure from step 1.
7		No	Inspect the related wiring harnesses and connectors. • Repair or replace the malfunctioning location. Go to the troubleshooting procedure to perform the procedure from repair completion verification.
8	PURPOSE: DETERMINE IF MALFUNCTION IS CAUSED BY VARIABLE TURBINE GEOMETRY TURBOCHARGER ACTUATOR POSITION SENSOR MALFUNCTION • Inspect the variable turbine geometry turbocharger actuator position sensor. (See ACTUATOR POSITION SENSOR (TURBOCHARGER WITH VARIABLE TURBINE GEOMETRY) INSPECTION [SKYACTIV-D 1.8].) • Is the variable turbine geometry turbocharger actuator position sensor normal?	Yes	Go to Troubleshooting Diagnostic Procedure to perform the procedure from step 1.
8		No	Inspect the related wiring harnesses and connectors. • Repair or replace the malfunctioning location. Go to the troubleshooting procedure to perform the procedure from repair completion verification.

• Repair completion verification

Step	Inspection	Results	Action
1	PURPOSE: INSPECT TURBOCHARGER SOLENOID VALVE FOR MALFUNCTION • Inspect the applicable part. (See TURBOCHARGER SOLENOID VALVE INSPECTION [SKYACTIV-D 1.8].) • Is the part normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See TURBOCHARGER WITH VARIABLE TURBINE GEOMETRY REMOVAL/INSTALLATION [SKYACTIV-D 1.8].)
2	INSPECT VARIABLE TURBINE GEOMETRY TURBOCHARGER ACTUATOR FOR MALFUNCTION • Inspect the applicable part. (See TURBOCHARGER WITH VARIABLE TURBINE GEOMETRY INSPECTION [SKYACTIV-D 1.8].) • Is the part normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See TURBOCHARGER WITH VARIABLE TURBINE GEOMETRY REMOVAL/INSTALLATION [SKYACTIV-D 1.8].)
Repair completion verification 1	PURPOSE: VERIFY THAT VEHICLE IS REPAIRED • Install/connect the part removed/disconnected during the troubleshooting procedure. • Clear the DTC recorded in the memory. (See CLEARING DTC.) • Replicate the vehicle conditions at the time the DTC was detected using the following procedure. ― Implement the repeatability verification procedure. (See Repeatability Verification Procedure) • Perform the DTC inspection for the PCM. (See DTC INSPECTION.) • Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 1.8].)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	PURPOSE: VERIFY IF OTHER DTCs DISPLAYED • Perform the DTC inspection. (See DTC INSPECTION.) • Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.

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