DTC P0172:00 [L3 Turbo]SM2444175
DTC P0172:00 [L3 Turbo]

id0102b7934300

DTC P0172:00

Fuel trim system too rich
DETECTION CONDITION
• The PCM monitors short fuel trim (SHRTFT) and long fuel trim (LONGFT) values when closed loop fuel control. If the LONGFT and the sum total of these fuel trims exceed preprogrammed criteria, the PCM determines that the fuel system is too rich.
Diagnostic support note
• This is a continuous monitor (fuel system).
• The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
• PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
• FREEZE FRAME DATA (Mode 2)/Snapshot data is available.
• DTCs are stored in the PCM memory.
POSSIBLE CAUSE
• Erratic signal to PCM
― APP sensor signal malfunction
― ECT sensor signal malfunction
― MAF sensor signal malfunction
― TP sensor signal malfunction
― VSS signal malfunction
― Related connector or terminals malfunction
― Related wiring harness malfunction
• A/F sensor heater malfunction
• A/F sensor looseness
• Exhaust system leakage
• A/F sensor deterioration
• MAF sensor malfunction
• Improper operation of purge control system
― Purge solenoid valve malfunction (stuck open)
― Improper connection of purge solenoid hoses
• Improper operation of EGR valve system
• Improper operation of variable swirl control
• Improper operation of variable valve timing control system
• High-pressure side fuel delivery system malfunction
― Fuel pressure sensor (built-in fuel delivery pipe) malfunction
― Relief valve (built-in fuel delivery pipe) malfunction
― Spill valve control solenoid valve (built-in high pressure fuel pump) malfunction
― High pressure fuel pump malfunction
• Low-pressure side fuel delivery system malfunction
― Fuel pressure regulator (built-in fuel pump unit) malfunction
― Fuel pump unit malfunction
― Fuel filter clogging
― Fuel leakage on fuel line (between fuel pump unit and high pressure fuel pump)
• Ignition system malfunction
― Spark plug malfunction
― Ignition coil malfunction
― Ignition coil related wiring harness malfunction
• Improper operation of PCV valve
• Improper fuel injector operation
• Misfire
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA (MODE 2)
• Perform the Freeze Frame PID Data Access Procedure. (See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].)
• Is the DTC P0172:00 on FREEZE FRAME DATA (Mode 2)?
Yes
Go to the next step.
No
Go to the troubleshooting procedures for DTC on FREEZE FRAME DATA (Mode 2).
(See DTC TABLE [L3 Turbo].)
2
VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED
• Have the snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (fuel system related) been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
3
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
• Verify related Service Information availability.
• Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
• If the vehicle is not repaired, go to the next step.
No
Go to the next step.
4
VERIFY RELATED PENDING CODE AND STORED DTC
• Turn the ignition switch off, then to the ON position (engine off).
• Perform the DTC Reading Procedure and Pending Trouble Code Access Procedure. (See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].)
• Are any other DTCs present?
Yes
If misfire DTC is present:
• Go to Step 11.
If other DTC is present:
• Go to the applicable DTC inspection. (See DTC TABLE [L3 Turbo].)
No
If drive ability concern is present:
• Go to Step 11.
If drive ability concern is not present:
• Go to the next step.
5
VERIFY CURRENT INPUT SIGNAL STATUS (IGNITION SWITCH TO THE ON POSITION/IDLE)
• Access the following PIDs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].)
― APP1
― APP2
― ECT
― MAF
― TP REL
― VSS
• Is there any signal that is far out of specification when the ignition switch is at the ON position and the engine runs? (See PCM INSPECTION [L3 Turbo].)
Yes
Inspect the suspected circuit.
• If there is any malfunction:
― Repair or replace the malfunctioning part according to the inspection results, then go to Step 24.
No
Go to the next step.
6
VERIFY CURRENT INPUT SIGNAL STATUS UNDER FREEZE FRAME DATA (MODE 2) CONDITION
• Access the same PIDs as in Step 5 while simulating the FREEZE FRAME DATA (Mode 2) condition. (See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].)
• Is there any signal which causes drastic changes?
Yes
Inspect the suspected circuit.
• If there is any malfunction:
― Repair or replace the malfunctioning part according to the inspection results, then go to Step 24.
No
Go to the next step.
7
INSPECT A/F SENSOR HEATER
• Inspect the A/F sensor heater. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [L3 Turbo].)
• Is there any malfunction?
Yes
Replace the A/F sensor, then go to Step 24.
(See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [L3 Turbo].)
No
Go to the next step.
8
INSPECT A/F SENSOR
• Reconnect all disconnected connectors.
• Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [L3 Turbo].)
• Is there any malfunction?
Yes
Go to the next step.
No
Go to Step 11.
9
INSPECT INSTALLATION OF A/F SENSOR
• Inspect if the A/F sensor is loosely installed.
• Is the A/F sensor installed securely?
Yes
Go to the next step.
No
Retighten the A/F sensor, then go to Step 24.
(See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [L3 Turbo].)
10
INSPECT EXHAUST GAS LEAKAGE
• Visually inspect for the exhaust gas leakage between the exhaust manifold and A/F sensor.
• Is there any leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 24.
No
Replace the A/F sensor, then go to Step 24.
(See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [L3 Turbo].)
11
VERIFY CURRENT INPUT SIGNAL STATUS OF MAF SENSOR
• Start the engine.
• Access the MAF PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].)
• Verify that the MAF PID changes quickly according to engine speed.
• Is the MAF PID value normal? (See PCM INSPECTION [L3 Turbo].)
Yes
Go to the next step.
No
Replace the MAF/IAT sensor, then go to Step 24.
(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [L3 Turbo].)
12
INSPECT PURGE CONTROL SYSTEM OPERATION
• Perform the Purge Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L3 Turbo].)
• Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 24.
No
Go to the next step.
13
INSPECT EGR VALVE OPERATION
• Perform the EGR Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L3 Turbo].)
• Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 24.
No
Go to the next step.
14
INSPECT VARIABLE SWIRL CONTROL OPERATION
• Perform the Variable Swirl System Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L3 Turbo].)
• Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 24.
No
Go to the next step.
15
INSPECT VARIABLE VALVE TIMING CONTROL SYSTEM OPERATION
• Perform the Variable Valve Timing Control System Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L3 Turbo].)
• Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 24.
No
Go to the next step.
16
INSPECT FUEL PRESSURE (HIGH-SIDE)
• Access the FUEL_PRES PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].)
• Is the FUEL_PRES PID value within the specification? (See PCM INSPECTION [L3 Turbo].)
Yes
Go to Step 20.
No
Go to the next step.
17
IDENTIFY CAUSE BY FUEL PRESSURE SENSOR OR HIGH PRESSURE FUEL PUMP
• Is the vehicle accelerate performance normally?
Yes
Go to the next step.
No
Go to Step 19.
18
INSPECT FUEL PRESSURE SENSOR
• Inspect the fuel pressure sensor. (See FUEL PRESSURE SENSOR INSPECTION [L3 Turbo].)
• Is there any malfunction?
Yes
Replace the fuel delivery pipe, then go to Step 24.
(See FUEL INJECTOR REMOVAL/INSTALLATION [L3 Turbo].)
No
Go to the next step.
19
INSPECT HIGH PRESSURE FUEL PUMP
• Replace the high pressure fuel pump (See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [L3 Turbo].)
• Access the FUEL_PRES PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].)
• Is the FUEL_PRES PID value within the specification? (See PCM INSPECTION [L3 Turbo].)
Yes
High-pressure fuel pump or spill valve control solenoid valve (built-in high pressure fuel pump) malfunction.
• Go to Step 24.
No
Go to the next step.
20
INSPECT FUEL PRESSURE (LOW-SIDE)
• Connect the fuel pressure gauge between fuel pump and high pressure fuel pump.
• Measure the low side fuel pressure. (See FUEL LINE PRESSURE INSPECTION [L3 Turbo].)
• Is the low side fuel pressure within the specification?
Yes
Go to the next step.
No
Inspect for the following.
• Fuel line restriction
• Fuel filter clogging
― If there is no malfunction:
• Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L3 Turbo].)
― If there is any malfunction:
• Repair or replace the malfunctioning part according to the inspection results.
Go to Step 24.
21
INSPECT IGNITION SYSTEM OPERATION
• Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L3 Turbo].)
• Is a strong blue spark visible at each cylinder?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the spark test result, then go to Step 24.
22
INSPECT PCV VALVE OPERATION
• Inspect the PCV valve operation. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [L3 Turbo].)
• Is there any malfunction?
Yes
Replace the PCV valve, then go to Step 24.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [L3 Turbo].)
No
Go to the next step.
23
INSPECT FUEL INJECTOR OPERATION
• Perform the Fuel Injector Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L3 Turbo].)
• Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to the next step.
No
Go to the next step.
24
VERIFY DTC TROUBLESHOOTING COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [L3 Turbo].)
• Perform the Drive Mode 03 (EGR System, A/F sensor heater, HO2S heater, A/F sensor, HO2S, and TWC Repair Verification Drive Mode). (See OBD DRIVE MODE [L3 Turbo].)
• Stop the vehicle and access the ON BOARD READINESS TEST to inspect Drive Mode completion status.
• Verify the FUEL_EVAL PID changes to yes.
― If not:
• Perform the Drive Mode 03 (EGR System, A/F sensor heater, HO2S heater, A/F sensor, HO2S, and TWC Repair Verification Drive Mode). (See OBD DRIVE MODE [L3 Turbo].)
• Perform the KOER self test. (See KOEO/KOER SELF TEST [L3 Turbo].)
• Is the PENDING CODE for this DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [L3 Turbo].)
No
Go to the next step.
25
VERIFY AFTER REPAIR PROCEDURE
• Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [L3 Turbo].)
• Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [L3 Turbo].)
No
DTC troubleshooting completed.