hi im new here just done 240 mls and pickup my 1st z well happy got 10 mls from home the engine light came on still ran fine got me home ok still got a big smile any one help what it can be ie ecu?ted

Congratulations and welcome to the forum. I wish I could help.

The only thing I would suggest is, it may be worth disconnecting the battery for 30 minutes so as to re set the ECU.

Maybe worth holding out for some of the more knowledgable members to come along though.

ok cheers fella ill give that a go

No, don't just reset the ECU, find out what the code is first! It's happened for a reason and it's a 5 minute job.

 

The ECU is located in the passenger-side footwell. Pull back the carpet (velcroed in place), undo 4 bolts holding the wooden kickplate in place. ECU is revealed!

 

On the RHS of the ECU you will find the Self-Diagnostic screw, and to the right of this you will see a small window housing a red LED.

 

Turn ign to ACC (don't start the car). The LED will light up and you will have lights on the dash, the important one being the Check Engine Light (CEL).

Using a flat-head screwdriver, rotate the ECU screw fully clockwise, keep it there for 3 secs, then rotate it fully anti-clockwise to its original position (Remember this sequence)

 

The LED & CEL will both start to blink, beginning with long flashes, followed by short ones.

 

Here are the codes:

11: Crank Angle Sensor (CAS) Circuit

12: Air Flow Meter Circuit (AFM/MAF)

13: Engine Coolant Temp. Sensor Circuit

14: Vehicle Speed Sensor Circuit

21: Ignition Signal Circuit

26: Boost Pressure Sensor

31: ECU

32: Exhaust Gas Recirculation (EGR) Function

33: Exhaust Gas Sensor Circuit (Lambda) (Left)

34: Detonation Sensor Circuit

35: Exhaust Gas Temp. Sensor Circuit

42: Fuel Temp. Sensor Circuit

43: Throttle Position Sensor (TPS) Circuit

45: Injector Leak

51: Injector Circuit

53: Exhaust Gas Sensor Circuit (Lambda) (Right)

54: Signal Circuit From A/T Control To ECU

55: NO FAULTS

 

The faults in BOLD are the ones you will be interested in, as these cause the CEL to light whilst driving.

 

No faults would be represented by the following flashes: __ __ __ __ __ *Pause* _ _ _ _ _

 

You can check the functioning (or lack thereof) of the O2 sensors as well. When you're in Self-Diag. mode, start the car and let the engine get up to temperature. The LED/CEL is now indicating the voltage input from the LHS O2 sensor. Hold the engine at fast idle and you should see the LED/CEL blink approximately once every 2 seconds, as the sensor switches between lean/rich & low/high voltage. To check the operation of the RHS O2 sensor, simply rotate the screw fully clockwise, wait 3 secs, then rotate fully anti-clockwise.

 

Exit the Self-Diagnostic mode by one of two ways: Turning the key off keeps the codes stored; turning the screw fully clockwise, waiting 3 secs, and then returning it once again fully anti-clockwise clears the codes. Note that you can also get into Self-Diag mode by shorting two pins of the Consult port, but you'll be wanting to access your ECU anyway (see below). ECU codes are only any good when a circuit fails completely. A sensor giving the wrong information will not be recorded. This is where Consult diagnosis comes into play.

 

Best thing you can do when getting a new Zed are a few simple things (in no particular order, and pertaining to engine-related systems only):

• Check which ECU you're running (Jap Spec = 98RON+ only IMO) and whether it's been chipped or not. If it has, get it checked out, assume nothing!
  
• Set the TPS
  
• Set the idle
  
• Tighten the throttle cable (first thing I do with any new car) and sync the throttle bodies
  
• Clean the MAF wire carefully (I use acetone)
  
• New spark plugs (cyls 5&6 are a pain, mine were different to the front four when I got the car)
  
• New fuel filter (cheap & a five minute job)
  
• Check boost levels
  
• Find the myriad vacuum leaks and brittle pipes and rectify
  
• Check as many electrical connections as possible for corrosion, particularly the injectors & the sensors at the rear (ISCV, AAC etc). Be careful, the heat will have made everything brittle and things will break. WD40 is your friend.
  
• Check the base timing is set at 15° BTDC. Use a HT lead extension between coil pack & plug on cyl 1, don't waste time trying to use the inductive loop near the PTU or the coil pack loom. Rotate the CAS clockwise to retard timing; anti-clockwise to advance.
  
• Expect the Series 1 PTU to screw up. I've stripped back the wires and left mine over near the nearside wing. There are better places. Replace with Series 2 PTU if goosed. (I used a spare S1 off my GTR)
  

 

Hope that helps!

top man im going to be on that right now let you know how i get on cheers ted

Some, excellent advise there above from Noz however be aware that the ONLY thing that can bring the engine management light on when running is to do with the ecu itself, the system is a basic OB1 type and cannot self report via the engine light unless promted to do so by starting the diagnostic test as mentioned by Noz.

 

A corrupted chip, a loose chip, a bad solder on the chip socket or even a loose ecu main connector is where the fault will be.

 

Good luck with the new purchase and welcome to the forum, sure you will get it sorted from help here.

 

Jeff TT

Edited September 15, 201213 yr by JeffTT

Hi guys, sorry for the hijack but my OEM ECU (auto trans) on my 1989 300zx TT Z32 does not have a pot or led. I know this because I have opened it up and removed the chip and fitted a socket and upgrade chip. I know of no other 300 with this type. This car was a Jap import and originally an auto now manual gearbox.

How do I do diagnosis except with a consult of course?

Cheers

hi m8 just found a grey plug at the back of the engine more by the batt its black and mustard wires that was snaped and all that someone done is a 10 bob fix and a small hose that goes to the left bank was to small as it came from the bank to the sencer it was clamped on the bend so hope when i get the plug put on that be it ted

Hi guys, sorry for the hijack but my OEM ECU (auto trans) on my 1989 300zx TT Z32 does not have a pot or led. I know this because I have opened it up and removed the chip and fitted a socket and upgrade chip. I know of no other 300 with this type. This car was a Jap import and originally an auto now manual gearbox.

How do I do diagnosis except with a consult of course?

Cheers

 

Interesting! What's the part number of the ECU?

 

You can enter Self Diag. mode by bridging 2 pins of the Consult socket under the dash.

 

As you look at the plug, hold it so the rounded end is to the right. You would then bridge the 2 left-hand pins on the bottom row.

 

| - | - | - | - | - )

|0 |0 | - | - | - )

 

^^ God knows what that will look like, but it should make sense :D

Thanks NOZ, I will pull it out and check out the number. Will also bridge out the 2 pins.

Thanks

hi m8 just done ecu and got 5 long and 5 short flashes i think you put down its fine or is that not right? cheers ted

Hi guys, sorry for the hijack but my OEM ECU (auto trans) on my 1989 300zx TT Z32 does not have a pot or led. I know this because I have opened it up and removed the chip and fitted a socket and upgrade chip. I know of no other 300 with this type. This car was a Jap import and originally an auto now manual gearbox.

How do I do diagnosis except with a consult of course?

Cheers

 

You do now - mines not got one either on a 93 UK car! There are quite a few like this actually

 

I have always shorted out the 2 pins on the consult port as described above by Noz & this works fine (now got a datascan so no need to mess around anymore! Well worth getting for any zed owner IMO)

 

:)

No, don't just reset the ECU, find out what the code is first! It's happened for a reason and it's a 5 minute job.

 

The ECU is located in the passenger-side footwell. Pull back the carpet (velcroed in place), undo 4 bolts holding the wooden kickplate in place. ECU is revealed!

 

On the RHS of the ECU you will find the Self-Diagnostic screw, and to the right of this you will see a small window housing a red LED.

 

Turn ign to ACC (don't start the car). The LED will light up and you will have lights on the dash, the important one being the Check Engine Light (CEL).

Using a flat-head screwdriver, rotate the ECU screw fully clockwise, keep it there for 3 secs, then rotate it fully anti-clockwise to its original position (Remember this sequence)

 

The LED & CEL will both start to blink, beginning with long flashes, followed by short ones.

 

Here are the codes:

11: Crank Angle Sensor (CAS) Circuit

12: Air Flow Meter Circuit (AFM/MAF)

13: Engine Coolant Temp. Sensor Circuit

14: Vehicle Speed Sensor Circuit

21: Ignition Signal Circuit

26: Boost Pressure Sensor

31: ECU

32: Exhaust Gas Recirculation (EGR) Function

33: Exhaust Gas Sensor Circuit (Lambda) (Left)

34: Detonation Sensor Circuit

35: Exhaust Gas Temp. Sensor Circuit

42: Fuel Temp. Sensor Circuit

43: Throttle Position Sensor (TPS) Circuit

45: Injector Leak

51: Injector Circuit

53: Exhaust Gas Sensor Circuit (Lambda) (Right)

54: Signal Circuit From A/T Control To ECU

55: NO FAULTS

 

The faults in BOLD are the ones you will be interested in, as these cause the CEL to light whilst driving.

 

No faults would be represented by the following flashes: __ __ __ __ __ *Pause* _ _ _ _ _

 

You can check the functioning (or lack thereof) of the O2 sensors as well. When you're in Self-Diag. mode, start the car and let the engine get up to temperature. The LED/CEL is now indicating the voltage input from the LHS O2 sensor. Hold the engine at fast idle and you should see the LED/CEL blink approximately once every 2 seconds, as the sensor switches between lean/rich & low/high voltage. To check the operation of the RHS O2 sensor, simply rotate the screw fully clockwise, wait 3 secs, then rotate fully anti-clockwise.

 

Exit the Self-Diagnostic mode by one of two ways: Turning the key off keeps the codes stored; turning the screw fully clockwise, waiting 3 secs, and then returning it once again fully anti-clockwise clears the codes. Note that you can also get into Self-Diag mode by shorting two pins of the Consult port, but you'll be wanting to access your ECU anyway (see below). ECU codes are only any good when a circuit fails completely. A sensor giving the wrong information will not be recorded. This is where Consult diagnosis comes into play.

 

Best thing you can do when getting a new Zed are a few simple things (in no particular order, and pertaining to engine-related systems only):

• Check which ECU you're running (Jap Spec = 98RON+ only IMO) and whether it's been chipped or not. If it has, get it checked out, assume nothing!
  
• Set the TPS
  
• Set the idle
  
• Tighten the throttle cable (first thing I do with any new car) and sync the throttle bodies
  
• Clean the MAF wire carefully (I use acetone)
  
• New spark plugs (cyls 5&6 are a pain, mine were different to the front four when I got the car)
  
• New fuel filter (cheap & a five minute job)
  
• Check boost levels
  
• Find the myriad vacuum leaks and brittle pipes and rectify
  
• Check as many electrical connections as possible for corrosion, particularly the injectors & the sensors at the rear (ISCV, AAC etc). Be careful, the heat will have made everything brittle and things will break. WD40 is your friend.
  
• Check the base timing is set at 15° BTDC. Use a HT lead extension between coil pack & plug on cyl 1, don't waste time trying to use the inductive loop near the PTU or the coil pack loom. Rotate the CAS clockwise to retard timing; anti-clockwise to advance.
  
• Expect the Series 1 PTU to screw up. I've stripped back the wires and left mine over near the nearside wing. There are better places. Replace with Series 2 PTU if goosed. (I used a spare S1 off my GTR)
  

 

Hope that helps!

 

hi cheers for the info engine light now gone 1 damaged plug and cleaned all the other plugs checked the ecu 5 long 5 short flashes so well happy many thanks to all of you guys

Sorry to rain on your parade Ted but you have not found the fault yet, as I mentioned before the ecu is an early OBC1 type and cannot under any circumstances self report by bringing the engine management light on, shorts and bad connection under the bonnet will not cause this only the ecu issues I mentioned earlier on in the thread.

 

Having re-read the answer by Noz I have to disagree that any of the items he has put in bold will cause an engine mangement light to come on, the ecu is not equiped that way, in fact the number of engines regularly reported to be running poorly here usually caused by bad or disconnected connections is in the hundreds non will report an engine mangagement light event.The list added by Noz has items such as injector leaking and egr valve issues, neither the egr valve or injectors can report back in any way they are not functioning? the egr valve has no electrical connection at all if an injector goes open circuit it just does not work with no engine light, if the injector shorts out the output from the ecu to that injector overloads and damages the ecu there is no protection to the injector outputs at all within the ecu, if the egr valve is removed then no light either

 

The list posted by Noz is INCORRECT and as is often the case has most likely been lifted off the internet somewhere maybe even here when the same question was answered incorrectly before, this is easily done and no disrespect to Noz he was only trying to help.

 

A corrupted chip, a loose chip, a bad solder on the chip socket or even a loose ecu main connector is where the fault will be, whilst doing a code check at the ecu you have unwittingly disturbed the bad connection and made it good but chances are the fault may reappear in time.

 

Jeff TT

Edited September 15, 201213 yr by JeffTT

hi jeff so im going to pull ecu in the morning and get it checked out as i think ill do more harm than good nos done me favour as i found the damaged plug as i wouldnt have looked for it but ill get it checked out and let you know how it turns out cheers ted

hi jeff so im going to pull ecu in the morning and get it checked out as i think ill do more harm than good nos done me favour as i found the damaged plug as i wouldnt have looked for it but ill get it checked out and let you know how it turns out cheers ted

 

 

Yes thats all good, we all here to help and thats what matters.

 

Good luck

 

Jeff TT

Sorry to rain on your parade Ted but you have not found the fault yet, as I mentioned before the ecu is an early OBC1 type and cannot under any circumstances self report by bringing the engine management light on, shorts and bad connection under the bonnet will not cause this only the ecu issues I mentioned earlier on in the thread.

 

Having re-read the answer by Nos I have to disagree that any of the items he has put in bold will cause an engine mangemnet light to come on, the ecu is not equiped that way, in fact the number of engines regularly reported to be running poorly here usually caused by bad or disconnected connections is in the hundreds non will report an engine mangagement light event.The list added by Nos has items such as injector leaking and egr valve issues, neither the egr valve or injectors can report back in any way they are not functioning? the egr valve has no electrical connection at all if an injector goes open circuit it just does not work with no engine light, if the injector shorts out the output from the ecu to that injector overloads and damages the ecu there is no protection to the injector outputs at all within the ecu, if the egr valve is removed then no light either

 

The list posted by Nos is INCORRECT and as is often the case has most likely been lifted off the internet somewhere maybe even here when the same question was answered incorrectly before.

 

A corrupted chip, a loose chip, a bad solder on the chip socket or even a loose ecu main connector is where the fault will be, chances are the fault may reappear in time.

 

Jeff TT

 

Calm down fella.

 

Of course the list of codes is taken from various online sources, they are provided here in order to help. The codes given ARE correct. It is information to help him find the issue, and general information as he has just bought the car. I myself have never used the Self Diag mode as I have umpteen programs that communicate directly with nearly any ECU from any manufacturer. If he's ever nearby to me, he is more than welcome to pop on over and I will gladly hook up my laptop to see if there's anything amiss, or check over the ECU itself. The rest of the post is from my experience with the Zed and Nissans in general.

 

I've just been outside and disconnected the MAF plug whilst the car was running, and the CEL remained off, which does indeed mean that you won't get a CEL when driving. So, please ignore the bold in the list. The list that I didn't compile from memory. Shock horror :laugh: I don't know all the OBDII codes off by heart either! The shame!

 

And Jiff, it's "NOZ".

 

Ta.

guys i apperciate all the help you all given me ill get there in the end and i think i owe you apology i used (nos) should have been noz cheers ted

guys i apperciate all the help you all given me ill get there in the end and i think i owe you apology i used (nos) should have been noz cheers ted

 

Heh, hardly dude, it was tongue-in-cheek :)

hi just got back from a d popes the ecu wasnt pluged in right the small one under it was new and when you look at the blue plug 1 pin was shorter but all done many thanks ted

Ahem.

 

Jeff TT

Edited September 16, 201213 yr by JeffTT

Glad you got it sorted mate.

Enjoy.

Ahem.

 

Jeff TT

 

Jeff TT

 

lol... yeah, I think he meant "Thanks Jeff"....

yea def cheers jeff you put me on the right path top man