DTC P1491: EGR SYSTEM MALFUNCTION 1. Perform PCM reset procedure. Connect SCS service connector. Start engine and run at 3000 RPM with no loads and transmission in Park or Neutral, until radiator fan comes on. Drive vehicle for approximately 10 minutes. Maintain engine speed at 1700-2500 RPM. If DTC P1491 is indicated, go to next step.

P1491-RAD FAN CONTROL RELAY CIRCUIT. When Monitored: With the ignition key on, battery voltage greater than 10.0 volts and. the PCM requests the radiator fan to be turned on. Set Condition: An open or shorted circuit is detected in the radiator fan relay control. circuit. POSSIBLE CAUSES. RADIATOR FAN CTRL RLY CIRCUIT WIRE …

Customer: p1491 code coming up on a 2003 Nissan Xterra SE/SC. It is stated as the "vacuum cut valve bypass valve". It is stated as the "vacuum cut valve bypass valve". What are the steps to verify exactly what is the problem and what needs to be replaced?

Aside from the P1491 code and TCS light the car tends to occasionally lurch forward on slow acceleration. I am pushing down the pedal with no immediate response and then it suddenly lurches. Could this be a EGR issue or do you think that something else is wrong.

The code P1491 comes up as radiator fan delay circut open for Dodge/Chrysler. I mean "frynig" as in the Relay gets so hot that it starts to melt the plastic on it and the (PDC). "P1491 †Malfunction In EGR System" is for Honda and Acura

DTC P1491 - EGR SYSTEM 1. Perform PCM reset procedure. Connect SCS service connector. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator cooling fan comes on. Drive vehicle for approximately 10 minutes. Maintain engine speed at 1700-2500 RPM.

P1491 is for the a/c condensor fan's relay control circuit. Open the fuse box under the hood and you should find fuse number 39 is blown. If it is, you'll need to replace the condensor fan assembly. Most likely the motor has failed and caused it to blow.

Customer: Hi, I have a 2010 Subaru Forester 2.5i with a persistent P1491 code for the blow by sensor. I've put in a new pcv valve and also replaced the sensor with another on (used) a couple times. I've put in a new pcv valve and also replaced the …

I am getting trouble code P1491 on my Dodge Ram 1500 - yr 2002. It says it is the radiator fan relay circuit.

Shop told me they traced my wires upto the PCM. PCM was recieving but was not transmitting that the cooling fan needed to be activated. As of wires C1 and C2. $50 for diagnoses. OK. Ordered PCM from J & W Jeep Recyclers $250. Installed. Still reads codes as follows. P1491-Radiator Fan Control Relay Circuit.