Reductant circuit
To check whether reductant is reaching the reductant doser:Check whether the reductant in the reductant circuit has frozen.Run EEC > E67 > EEC3 > Exhaust gas aftertreatment, troubleshooting > Troubleshooting guide. To check whether there is a fault in the pressure sensor in the reductant doser: Check the pressure sensor value using SDP3. Ensure that the reductant pump is shut off. The pressure should be between -0.5 and 0.8 bar when the reductant pump has been shut off for more than 3 minutes. If the pressure is outside this range, renew the reductant doser. The pressure sensor value normally varies when readings are taken. If the value is constant, remove the hoses to the reductant doser. Then try to achieve a small change in pressure at the reductant doser inlet. If the pressure sensor does not react to this, renew the reductant doser.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
The reductant pump needs to run more quickly than expected to maintain the correct reductant pressure.
The fault arises when the reductant does not reach the reductant doser, or if the pressure sensor in the reductant doser gives values that are too low. The cause can be one of the following: Blockage or leakage in the reductant pick-up unit suction hose between the reductant tank and reductant pump. Blockage in the reductant pump prefilter or main filter. The overflow valve in the reductant pump opens when the pressure is too low. Blockage or leakage in the pressure pipe between the reductant pump and reductant doser. Blockage in the reductant doser prefilter. Fault in the reductant pump.