If you drive a Citroen C5 Aircross or a Peugeot with the 2.0L Diesel engine, experiencing a loss of power ("Limp Mode") is a common headache. When you scan the vehicle, you might be greeted by two specific codes: P0238 and P0098.
These codes indicate an issue with the Air Turbocharging Signal and Intake Air Temperature. In this guide, following the expert advice from SA Diagnostic's, we’ll show you how to tackle this problem systematically using the iCarsoft CR ULTRA P.
The sensor is located right on the air intake pipe, secured by a single bolt.Step 1: Don't Just Swap Parts—Check for Leaks
Before you spend money on sensors, rule out the obvious. As the video suggests, a split turbo hose can trigger these codes.
- Listen: Have someone rev the engine while you listen for hissing sounds.
- Inspect: Look for oily residue on pipes (a sign of a leak).
- Smoke Test: Most garages can perform a smoke test to find hidden cracks.
You can also use your iCarsoft CR ULTRA P to view Live Boost Pressure. If the sensor reads atmospheric pressure but doesn't rise when you rev, and you hear no air escaping, the sensor is the prime suspect.
Video Tutorial: Sensor Location & Fix
Watch the full diagnostic process here:
Step 2: Clean or Replace the Sensor
The culprit is usually the MAP (Manifold Absolute Pressure) Sensor, which often houses the temperature sensor too (hence both P0238 and P0098 codes).
The "Clean First" Method:
- Remove the single bolt (Size 8 or 10) holding the sensor.
- Pull the sensor out gently.
- Clean it with Electrical Contact Cleaner to remove oil and soot.
- Reinstall and test.
Check the Throttle Body: The video also notes that the throttle valve (located nearby) can get clogged with carbon. Taking it off and cleaning it is a good preventative measure.
A simple cleaning can sometimes save you the cost of a new sensor.
Step 3: The Critical Reset (Adaptions)
Whether you clean the old sensor or install a new OEM Sensor (highly recommended), the job isn't done yet. The technician emphasizes:
"Reset the adaption with a diagnostic machine... if that doesn't work, it could be the sensor faulty."
This is where the iCarsoft CR ULTRA P is essential. Unlike basic code readers, it allows you to:
- Access the Engine Control Unit (ECU).
- Navigate to Adaptations / Initialization.
- Select "Reset Air Intake Adaptations".
This ensures the car's computer calibrates itself to the new sensor readings immediately.
Frequently Asked Questions (FAQ)
What if I just clear the codes?
Clearing codes removes the warning light temporarily, but if the "Adaptions" aren't reset, the ECU might still operate using old calibration data, leading to poor performance or the light coming back on.
Can I use an aftermarket sensor?
The video strongly advises: "Get original OEM... put it in." Aftermarket sensors often have slight voltage variances that trigger the P0238 High Input code instantly.
Does CR ULTRA P support other functions?
Yes, besides turbo systems, it handles DPF regeneration, Injector Coding, Battery Registration, and more for over 55 vehicle makes. View the full capabilities here.
Fix Your Boost Issues Today.
Don't guess with cheap tools. Get the iCarsoft CR ULTRA P for professional-grade diagnostics and adaptation resets.
