LJ78 2L-TE Correction Resistance (Fault Code 5)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Jan 1, 2022
Threads
9
Messages
32
Location
Anacortes, Washington
I believe the problem is the grey resistor on the side of the injection pump. Please correct me if I'm wrong. There are 2 resistors on the intake side of the injection pump. The forward one is grey. In my case it is measuring 12-20 M ohm. The beige / orange resistor measured 620 ohm. Anything in the mega ohm range seems like nearly an open loop. A little time on youtube lead me to some guys who replaced the grey resistor on their 1KZ with a 1500 ohm resistor. I'm not interested in modding my LC.

I would like to know what the resistance is suppose to be so that I can maintain the factory settings. Or if code 5 is something else completely please correct me.

correction resistance.jpg
 

Here is something I just found! YEAH GOOGLE!​

Hilux Surf: Error 5 - Correction resistance (Pump)​

POSTED: JANUARY 11, 2014​

Error code 5 relates to a pair of resistors on the side of the injection pump, at least on the 2.4TD engine.

InjectorPumpPicture.jpg

These resistors are installed when the pump is calibrated and fine tune the timing and fuelling.



grey_ip_resistor.jpg
beige_ip_resistor.jpg



I measured both resistors. The grey one was 0.622kΩ while the beige one was open circuit. The insides are potted in epoxy, so I dug out the trusty Dremel and went in.

grey_ip_resistor_epoxy.jpg

The original epoxy.​

beige_ip_resistor_post_dremel.jpg

After a bit of Dremel action.​

You can see a pair of solder tabs sticking up - the original resistor, which I ground away, was soldered on here. Judging from the resistor body, it was no more than a standard 0.25W resistor.

The problem now was knowing what value the resistor was originally.

I managed to find a scan of the manual for the Denso injector pump. I’ve also converted it into a pdf.

From that, I was able to work out the resistance value from the part numbers. Here’s a list linking to the resistors which are available from Farnell. First, the grey one.

grey_ip_resistor_part_no.jpg

Now the beige one.

beige_ip_resistor_part_no.jpg

Solder the appropriate resistors in.

ip_resistors_soldered.jpg

Now they need sealing from the elements. Check they read ok on a multimeter first though! After a good clean in some isopropyl alcohol, I used some Sugru to seal them up.

ip_resistors_sugru.jpg

Instead of Sugru, you could use some proper potting compound or even some mastic, but ONLY neutral cure mastic. If the mastic smells of vinegar, don’t use it! The acetic acid released as it cures will eat into the resistor wires.

After all that, I reset the ECU and the code 5 had been eliminated.
 
I removed the resistors from the injection pump and cleaned them off. Then I tested again. The numbers matched the table above. It looks like a little rubbing alcohol did the trick. Cleaned up the plugs and reinstalled everything and the Code fault cleared.
 
I removed the resistors from the injection pump and cleaned them off. Then I tested again. The numbers matched the table above. It looks like a little rubbing alcohol did the trick. Cleaned up the plugs and reinstalled everything and the Code fault cleared.

Use vaseline or lithium spray grease in your connectors to help prevent corrosion and future connection problems. Glad you figured it out!
 

Users who are viewing this thread

Back
Top Bottom