Hi, all. I have a Jag stype 2005. Recently, I had check the engine light and scanned error code. It was P1549. I replaced IMT O-rings, but my jag still have the same error code. Do you have any similar experience or any suggestion? Please let me know. Thanks in advance.

 

jw, first off welcome to the forum.

Second, you really should follow proper forum protocol and go to the "New Members" section and introduce yourself. There are many benefits to doing so.

Third, please goto "User CP", "Edit Signature" and fill in your vehicle details "Save". It only takes seconds to do.

The following will aid in trouble shooting your IMT Valve, I believe you want to test the upper valve:


P1549. IMT Valve 1. CHECK THE RH IMT VALVE RESISTANCE

Disconnect the IMT valve electrical connector, PI30.
Measure the resistance between pins 1 and 2 of the IMT
valve.

Is the resistance 30 ohms?
Yes Goto B2

No

Install a new IMT valve. CLEAR the DTC. TEST the system for
normal operation.

B2 : CHECK THE POWER SUPPLY CIRCUIT TO
THE IMT VALVE 1.

Turn the ignition switch to the ON position.

Measure the voltage between IMT valve 1 electrical connector
PI30, pin 1 (NG) and GROUND.
Is the voltage greater than 10 volts?
Yes
Goto B3

Repair the circuit between the IMT valve 1 electrical connector
PI30, pin 1 (NG) and the Battery power bus 2.This circuit
includes the power distribution fuse box and the EMS control relay.
For additional information, refer to wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.

B3 : CHECK
CONTINUITY OF THE IMT VALVE 1 SIGNAL WIRE.

Disconnect the PCM electrical connector, PI01.

Measure the resistance between the IMT valve 1 electrical
connector PI30, pin 2 (OY) and the PCM electrical connector PI01,
pin 38

Is the resistance less than 5 ohms?

Yes Goto B4
Repair the circuit between the IMT valve 1 electrical connector
PI30, pin 2 (OY) and the PCM electrical connector PI01, pin 38 (OY).
For additional information, refer to wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.


B4 : CHECK IMT VALVE
SIGNAL WIRE FOR SHORT TO GROUND

Measure the resistance between PI30, pin 2 (OY) and
GROUND.
Is the resistance less than 10,000
ohms?
Yes

Repair the short to GROUND. For additional information,
refer to wiring diagrams. CLEAR the DTC. TEST the system for normal
operation.


No

Goto B5


B5 : CHECK IMT VALVE SIGNAL WIRE FOR
SHORT TO BATTERY

Connect the PCM electrical connector, PI01.
Turn the ignition switch to the ON position.
Check for a voltage at PI30, pin 2 (OY)




Is the voltage greater than 5 volts?

Yes Repair the short to battery. For additional information,
refer to wiring diagrams. CLEAR the DTC. TEST the system for normal
operation.


No
Install a new IMT valve. CLEAR the DTC. TEST the system for
normal operation. If the DTC is repeated, INSTALL a new PCM. CLEAR
the DTC. TEST the system for normal operation.

Please post back your findings.

 

LOL! Rick you're amazing. The OP is likely feeling he's in tech heaven. BP and heart rate- Returning Back to Normal. Stomach PH rising. Scalp Hair Follicles- Commenced Growing, Cancelled Psychotherapist appointment.....

 

I know this information is probably in the JTIS, but shouldn't it be a sticky...great test link.

 

Joycesjag. Thank you so much. This will help me a lot. I am sure I will post my findings. Again, thank you.

 

jw, I highly doubt that the valve itself is bad. I have never heard nor read that a valve went belly up. My guess is that there is a wiring problem. Have you had any work done lately?

Thanks Seth!

 

joycesjag, previously, I checked wiring and everything except valve. I took out imt valve and checked resistance. Upper valve looked fine, but lower one showed no resistance. When I checked pin 1 with red of my multimeter and pin 2 with black, no resistance. When I checked pin 1 with black and pin 2 with red, the resistance was 6 mega ohms. I strongly doubt that something went wrong with the lower valve. So, I ordered lower valve and am still waiting for it. Thank you for your advice. After I fix it, I will post the result. Happy X-mas.

 

Hi, all. IMT valve arrived today, and I put it back on intake manifold. Now, P1549 code disappear. So, I guess the old lower IMT valve was the source of problem. Thank you joycesjag for your advice. I really appreciate for your help. Happy holidays.

 

Excellent!

Seems to be very rare, thankfully.

 

I am glad to help. As JagV8 stated excellent DIY work!

I am interested as to what could have been the cause for the valve itself to fail though, hmmmm.

 

jwboys - where did you buy the imt valve ...

 

Very old thread. Online parts places such as forum sponsors, or Jag dealer.