DTC P20DF:00 [MZR-CD 2.2]


id0102f3166400

DTC P20DF:00

Urea pump pressure sensor circuit low

DETECTION CONDITION
•  The SCR control unit monitors input voltage from urea pump pressure sensor while the engine switch is on. If the input voltage is below 0.2 V for 2 sec., the SCR control unit determines that the urea pump pressure sensor circuit voltage is low.
Diagnostic support note
•  The MIL illuminates if the SCR control unit detects the above malfunction condition in first drive cycle.
•  The SCR warning light flashes if the SCR control unit detects the above malfunction condition in first drive cycle.
•  PENDING CODE is available if the SCR control unit detects the above malfunction condition during the first drive cycle.
•  FREEZE FRAME DATA (mode2) and snapshot data are available.
•  The DTC is stored in the SCR control unit memory.
POSSIBLE CAUSE
•  Urea pump pressure sensor short cord connector or terminal malfunction
•  Short to ground in wiring harness between urea pump pressure sensor terminal 1 and SCR control unit terminal 26
•  Short to ground in wiring harness between boost sensor terminal 2 and SCR control unit terminal 60
•  SCR control unit connector or terminal malfunction
•  Urea pump pressure sensor signal circuit and ground circuit are shorted to each other
•  Open circuit in the wiring harness between urea pump pressure sensor terminal 1 and SCR control unit terminal 26
•  Urea pump pressure sensor connector or terminal malfunction
•  Urea pump pressure sensor malfunction
•  SCR control unit malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAS BEEN RECORDED
•  Have FREEZE FRAME DATA (mode2) or snapshot data been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA (mode2) and snapshot data on the repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform the 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.
3
VERIFY CURRENT SIGNAL STATUS: IS CONCERN INTERMITTENT OR CONSTANT?
•  Clear the DTC from the PCM memory using the M-MDS.
•  Start the engine.
•  Is the PENDING CODE for this DTC present?
Yes
Go to the next step.
No
Intermittent concern exists.
Perform the “INTERMITTENT CONCERN TROUBLESHOOTING”.
4
INSPECT UREA PUMP PRESSURE SENSOR SHORT CORD CONNECTOR FOR POOR CONNECTION
•  Switch the ignition off.
•  Disconnect the urea pump pressure sensor short cord connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 14.
No
Go to the next step.
5
INSPECT UREA PUMP PRESSURE SENSOR CIRCUIT FOR SHORT TO GROUND
•  Urea pump pressure sensor short cord connector is disconnected.
•  Switch the ignition off.
•  Inspect for continuity between the following terminals and body ground:
―  Urea pump pressure sensor short cord terminal C (SCR control unit-side) and body ground
―  Urea pump pressure sensor short cord terminal D (SCR control unit-side) and body ground
•  Is there continuity?
Yes
If the short to ground circuit could be detected:
•  Repair or replace for a possible short to ground.
If the short to ground circuit could not be detected:
•  Replace the SCR control unit (short to ground in SCR control unit internal circuit).
Then go to Step 14.
No
Go to the next step.
6
INSPECT SCR CONTROL UNIT CONNECTOR FOR POOR CONNECTION
•  Switch the ignition off.
•  Disconnect the SCR control unit connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 14.
No
Go to the next step.
7
INSPECT UREA PUMP PRESSURE SENSOR SIGNAL AND GROUND CIRCUITS FOR SHORT TO EACH OTHER
•  Urea pump pressure sensor short cord and SCR control unit connectors are disconnected.
•  Inspect for continuity between urea pump pressure sensor short cord terminals D and E (SCR control unit-side).
•  Is there continuity?
Yes
Repair or replace the malfunctioning wiring harness, then go to Step 14.
No
Go to the next step.
8
INSPECT UREA PUMP PRESSURE SENSOR CIRCUIT FOR OPEN CIRCUIT
•  Urea pump pressure sensor and SCR control unit connectors are disconnected.
•  Switch the ignition off.
•  Inspect for continuity between the urea pump pressure sensor short cord (SCR control unit-side) terminal C and SCR control unit terminal (wiring harness-side) 26.
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for possible open circuit, then go to Step 14.
9
INSPECT UREA PUMP PRESSURE SENSOR CONNECTOR FOR POOR CONNECTION
•  Switch the ignition off.
•  Disconnect the urea pump pressure sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 14.
No
Go to the next step.
10
INSPECT UREA PUMP PRESSURE SENSOR CIRCUIT FOR SHORT TO GROUND
•  Urea pump pressure sensor and short cord connectors are disconnected.
•  Switch the ignition off.
•  Inspect for continuity between the following terminals and body ground:
―  Urea pump pressure sensor short cord terminal C (urea pump pressure sensor-side) and body ground
―  Urea pump pressure sensor short cord terminal D (urea pump pressure sensor-side) and body ground
•  Is there continuity?
Yes
Repair or replace the wiring harness for possible short to ground circuit, then go to Step 14.
No
Go to the next step.
11
INSPECT UREA PUMP PRESSURE SENSOR SIGNAL AND GROUND CIRCUITS FOR SHORT TO EACH OTHER
•  Urea pump pressure sensor and short cord connectors are disconnected.
•  Inspect for continuity between urea pump pressure sensor short cord terminals D and E (urea pump pressure sensor-side).
•  Is there continuity?
Yes
Repair or replace the malfunctioning wiring harness, then go to Step 14.
No
Go to the next step.
12
INSPECT UREA PUMP PRESSURE SENSOR CIRCUIT FOR OPEN CIRCUIT
•  Urea pump pressure sensor and SCR control unit connectors are disconnected.
•  Switch the ignition off.
•  Inspect for continuity between the urea pump pressure sensor (urea pump pressure sensor-side) terminal C and urea pump pressure sensor terminal (wiring harness-side) 1.
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for possible open circuit, then go to Step 14.
13
INSPECT UREA PUMP PRESSURE SENSOR
•  Inspect the urea pump pressure sensor.
•  Is there any malfunction?
Yes
Replace the urea pump, then go to the next step.
No
Go to the next step.
14
VERIFY TROUBLESHOOTING OF DTC P20DF:00 COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the SCR control unit memory using the M-MDS.
•  Switch the ignition ON for 2 sec.
•  Retrieve the DTC using the M-MDS.
•  Is the PENDING CODE for this DTC present?
Yes
Replace the SCR control unit, then go to the next step.
No
Go to the next step.
15
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.