Follow us on Twitter and win Autohex II Scan Tool for Kia and Hyundai (worth 945.00 USD)

P0472 Exhaust Pressure Sensor "A" Circuit Low

AutoHex Online Help: Hyundai SANTAFE(CM) 2008
Component Location
General Description

Differential pressure sensor(DPS) is piezzo electric type sensor. Sensing the differential pressure between in front of CPF and in the back of CPF, DPS outputs linear signal from 0~5V. Using output signal, DPS detects the amount of soot, sulfide, SOF(soluble organic fraction) to determine if CPF regeneration is needed.

?CPF regeneration : When vehicle is in steady speed condition and above normal engine loading condition, if differential pressure between before and after CPF is above the specified pressure, ECM considers that stored soot inside of CPF is excessive. In this condition, exhaust gas tempt. is raised by post injection 1 and 2 to warm CPF up to 550?~650?. In this high tempt, soot inside of CPF burns up naturally and this mechanism is called as "CPF regeneration".

Most of soot is burned up during regeneration process but a little amount of soot is not burned up and stored inside of CPF continuously. The stored soot decreases the efficiency of CPF slowly. DPS corrects CPF regeneration period and duration as comparing and calculating the differential pressure due to stored soot with the total distance covered.



DTC Description

P0472 is set when the voltage below 0.85V - mimimum output voltage of DPS - is detected for more than 0.6 sec.. This code is due to open in power circuit or short to ground in signal circuit.

DTC Detecting Condition

Item

Detecting Condition

Possible Cause

DTC Strategy

Voltage monitoring

DPS Wiring

DPS component

Reversly connected DPS hose line

Clogged DPS

Clogged CPF

inlet section

Enable Conditions

IG KEY "ON"

Threshold Value

Open in power circuit

Short to GND in signal circuit

Diagnostic Time

0.6 sec.

Fail Safe

Fuel cut

NO

Engine check lamp blinks.

Differential pressure considered as 10hPa.

Soot simulation ON mode activated

Regeneration mileage shorten

EGR Off

NO

Fuel Limit

NO

Check

Lamp

BLINK

Specification
Schematic Circuit Diagram
Signal Waveform & Data

Fig.1) This is the signal waveform of DPS at idle state. When CPF is new, 1.0~1.2V is outputted normally.

Fig.2) This is the waveform of DPS as accelerating.

note

As accelerating, DPS signal output voltage does not vary too much. Even when accelerator pedal is fully depressed,the signal voltage fluctuates just a little bit like "Fig. 2". However, the more CPF is used, the more waveform fluctuates.