Mazda Atenza: GJ 2.2 SKYACTIV-D DPF Differential Pressure Sensor Failure Causing Regeneration Failure

The SH-VPTS 2.2-litre diesel in the GJ Atenza uses a differential pressure sensor to measure the pressure drop across the diesel particulate filter and calculate soot loading. The sensor and its small-bore hose connections are exposed to exhaust heat cycling and condensed soot-laden moisture. When the sensor drifts or fails, the ECU receives an incorrect soot-load reading: it either never triggers a forced regen (allowing the DPF to block) or triggers continuous regen cycles that burn excess fuel and overheat the catalyst. A blocked DPF results in limp-home mode.

• DPF warning light illuminated, sometimes accompanied by engine management light and limp-home power restriction
• Noticeably more frequent or continuous DPF regeneration cycles indicated by elevated idle temperature and fuel consumption
• P2452 or P2453 DPF pressure sensor fault codes stored in the ECU
• Rough, hesitant power delivery and black smoke if the DPF has reached a blocked state

1. 1

   Scan for DPF-related codes: P2002 (DPF efficiency below threshold), P2452/P2453 (DPF pressure sensor range/performance).

2. 2

   With a live data scanner, compare sensor reading against expected pressure drop at idle and at 2000 rpm.

3. 3

   Inspect the two small silicone hoses connecting the sensor to the DPF taps for cracks or blockages.

4. 4

   Check for soot paste in the hose bores.

Parts involved: Differential, Diesel particulate filter.

$350 to $900 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Has the DPF warning light ever come on, and was the cause investigated?”
• “Has the vehicle been driven mainly on short trips or urban cycles?”
• “Has the DPF ever required forced regeneration or professional cleaning?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.