Engine Emmission Control: Diagnosis — Jaguar S-type I (1998-2004)

Engine Emmission Control: Diagnosis Jaguar S-type I

Diagnosis and Testing

Verify the customer concern by operating the system.
Visually inspect for obvious signs of mechanical or electrical damage.
If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
If the concern is not visually evident, refer to the SYMPTOM CHART in the appropriate article.

DTC	Description	Possible Source	Action
P1400	Differential Pressure Feedback EGR Sensor Circuit Low Voltage Detected	DPFE signal circuit shorted to ground or signal return. VREF shorted to ground or signal return. DPFEGR sensor failure. PCM failure.	Go To PINPOINT TEST A
P1401	Differential Pressure Feedback EGR Sensor Circuit High Voltage Detected	Damaged harness. Connector pins bent or corroded. Damaged PCM. Damaged DPFE sensor (internal open circuit).	Go To PINPOINT TEST B
P1409	EVR Control Circuit Malfunction	Damaged harness. EVR Control Circuit open/short circuit. Connector pins bent or corroded. Damaged PCM. Damaged fuse B69 at the FPDB. Damaged EVR solenoid.	Go To PINPOINT TEST C