Possible Causes

Possible causes are:

• DPFEGR SIG shorted to GND (P1400).
• DPFEGR SIG open (P1401).
• DPFEGR SIG shorted to PWR (P1401).
• VREF shorted to PWR (P1401).
• VREF shorted to GND (P1400).
• SIG RTN open (P1401).
• Damaged DPFEGR sensor (P1400 or P1401).
• Damaged PCM (P1400 or P1401).