mx5cartalk.com

My recent engine rebuild has left the car with some intermittent symptoms (slight miss under low RPM load, rich running) so I hooked an LED up to the diagnostic port, and for the first time since I've owned the car (14 years) it popped out some error codes, specifically 10, 13, 12 and 18.

Now these don't seem to line up nicely with any of the published guides on diagnostic port error codes, specifically 13 and 18 aren't mentioned, and 10 / 12 don't relate at all to anything that has changed on the car.

After much more googling, I discovered that NBs produce 4 digit error codes, i.e. mine is 10, 13, 12 and 18 = 0328 which means Knock signal (KS) circuit high input.

Now that makes a lot more sense, as the knock sensor got knocked around a bit (hehe) when the engine overheated, and it looks like it might be the cause of the rich running.

So off to the US to buy a new knock sensor; looks like about $130 shipped. Turns out rock auto have the knock sensor and a few other bits I'm looking for (headligth connectors without buying a whole new loom, coilpack insulators without buying a new coilpack etc)

Do you know if the code list you found is comparable for the NB8A?

also, would you be able to post/link the list of NB codes? (I assume the LED thing is the same as an NA with where you put the wires?)



I tried this a while back on my NB8A and got a code of sorts, but couldn't find a single thing about NB codes since every website was from a USA viewpoint and assumed you'd just plug into an OBD reader.

hks_kansei wrote:Do you know if the code list you found is comparable for the NB8A?

also, would you be able to post/link the list of NB codes? (I assume the LED thing is the same as an NA with where you put the wires?)



I tried this a while back on my NB8A and got a code of sorts, but couldn't find a single thing about NB codes since every website was from a USA viewpoint and assumed you'd just plug into an OBD reader.

I looked in the service manual for the codes. Not sure if the NB8A has the same codes though;

DTC TABLE

P0010 CMP actuator circuit ON NO 1 CCM (See 01–02A–18 DTC P0010)
P0011 CMP - timing over-advanced ON NO 2 CCM (See 01–02A–20 DTC P0011)
P0012 CMP - timing over-retarded ON NO 2 CCM (See 01–02A–21 DTC P0012)
P0031 HO2S heater control circuit low (front) ON NO 2 HO2S heater (See 01–02A–22 DTC P0031)
P0032 HO2S heater control circuit high (front) ON NO 2 HO2S heater (See 01–02A–24 DTC P0032)
P0037 HO2S heater control circuit low (rear) ON NO 2 HO2S heater (See 01–02A–26 DTC P0037)
P0038 HO2S heater control circuit high (rear) ON NO 2 HO2S heater (See 01–02A–27 DTC P0038)
P0101 MAF circuit range/performance problem ON NO 2 CCM (See 01–02A–29 DTC P0101)
P0102 MAF circuit low input ON NO 1 CCM (See 01–02A–30 DTC P0102)
P0103 MAF circuit high input ON NO 1 CCM (See 01–02A–32 DTC P0103)
P0106 BARO circuit performance problem ON NO 2 CCM (See 01–02A–34 DTC P0106)
P0107 BARO circuit low input ON NO 1 CCM (See 01–02A–35 DTC P0107
P0108 BARO circuit high input ON NO 1 CCM (See 01–02A–37 DTC P0108)
P0111 IAT circuit performance problem ON NO 2 CCM (See 01–02A–39 DTC P0111)
P0112 IAT circuit low input ON NO 1 CCM (See 01–02A–40 DTC P0112)
P0113 IAT circuit high input ON NO 1 CCM (See 01–02A–41 DTC P0113)
P0116 ECT circuit range/performance problem ON NO 2 CCM (See 01–02A–43 DTC P0116)
P0117 ECT circuit low input ON NO 1 CCM (See 01–02A–45 DTC P0117)
P0118 ECT circuit high input ON NO 1 CCM (See 01–02A–46 DTC P0118)
P0121 TP circuit range/performance problem ON NO 2 CCM (See 01–02A–48 DTC P0121)
P0122 TP circuit low input ON Yes 1 CCM (See 01–02A–50 DTC P0122)
P0123 TP circuit high input ON Yes 1 CCM (See 01–02A–51 DTC P0123)
P0125 Insufficient coolant temperature for closed loopfuel control ON NO 2 CCM (See 01–02A–53 DTC P0125)
P0126Coolant thermostat stuck to openON NO 2 Thermostat (See 01–02A–55 DTC P0126, P0128)
P0128 ON NO 2 Thermostat (See 01–02A–55 DTC P0126, P0128)
P0131 HO2S (front) no inversion (low voltage stuck) ON NO 2 CCM (See 01–02A–57 DTC P0131)
P0132 HO2S (front) no inversion (high voltage stuck) ON NO 2 CCM (See 01–02A–60 DTC P0132)
P0133 HO2S (front) circuit slow response ON NO 2 HO2S (See 01–02A–62 DTC P0133)
P0134 HO2S (front) circuit no activity detected ON NO 2 CCM (See 01–02A–65 DTC P0134)
P0138 HO2S (rear) circuit high input ON NO 2 CCM (See 01–02A–67 DTC P0138)
P0140 HO2S (rear) circuit no activity detected ON NO 2 CCM (See 01–02A–68 DTC P0140)
P0171 Fuel trim system too lean ON NO 2 Fuel (See 01–02A–70 DTC P0171)
P0172 Fuel trim system too rich ON NO 2 Fuel (See 01–02A–73 DTC P0172)
P0222 TP sensor circuit short (See 05–02–7 DTC P0222)
P0223 TP sensor circuit open (See 05–02–9 DTC P0223)
P0300 Random misfire detected Flash/ ON NO 1 or2 Misfire (See 01–02A–75 DTC P0300)
P0301 Cylinder 1 misfire detected Flash/ ON NO 1 or2 Misfire (See 01–02A–78 DTC P0301, P0302, P0303, P0304)
P0302 Cylinder 2 misfire detected Flash/ ON NO 1 or2 Misfire 
P0303 Cylinder 3 misfire detected Flash/ ON NO 1 or2 Misfire 
P0304 Cylinder 4 misfire detected Flash/ ON NO 1 or2 Misfire 
P0327 KS circuit low input ON NO 1 CCM (See 01–02A–80 DTC P0327)
P0328 KS circuit high input ON NO 1 CCM (See 01–02A–81 DTC P0328)
P0335 CKP sensor circuit malfunction ON NO 1 CCM (See 01–02A–82 DTC P0335)
P0340 CMP sensor circuit malfunction ON NO 1 CCM (See 01–02A–84 DTC P0340)
P0401 EGR flow insufficient detected ON NO 2 EGR (See 01–02A–86 DTC P0401)
P0402 EGR flow excessive detected ON NO 2 EGR (See 01–02A–88 DTC P0402)
P0420 Catalyst system efficiency below threshold ON NO 2 Catalyst (See 01–02A–89 DTC P0420)
P0442 EVAP control system leak detected (small leak) ON NO 2 Evaporative (See 01–02A–90 DTC P0442)
P0443 EVAP control system purge control valve circuitmalfunction OFF NO 1 Other – (See 01–02A–92 DTC P0443)
P0451 FTP sensor performance problem ON NO 2 CCM (See 01–02A–94 DTC P0451)
P0452 EVAP control system pressure sensor low input ON NO 2 CCM (See 01–02A–96 DTC P0452)
P0453 EVAP control system pressure sensor high input ON NO 2 CCM (See 01–02A–97 DTC P0453)
P0455 EVAP control system leak detected (gross leak) ON NO 2 Evaporative (See 01–02A–99 DTC P0455)
P0461 Fuel gauge sender unit circuit range/performance ON NO 2 CCM (See 01–02A–102 DTC P0461)
P0462 Fuel gauge sender unit circuit low input ON NO 2 CCM (See 01–02A–103 DTC P0462)
P0463 Fuel gauge sender unit circuit high input ON NO 2 CCM (See 01–02A–104 DTC P0463)
P0464 Fuel gauge sender unit circuit performanceproblem (slosh check) ON NO 2 CCM (See 01–02A–106 DTC P0464)
P0480 Cooling fan relay circuit OFF NO 2 CCM (See 01–02A–106 DTC P0480)
P0500 VSS circuit malfunction ON Yes 2 CCM (See 01–02A–108 DTC P0500)
P0505 IAC valve circuit malfunction ON NO 1 CCM (See 01–02A–112 DTC P0505)
P0506 Idle control system RPM lower than expected ON NO 2 CCM (See 01–02A–114 DTC P0506)
P0507 Idle control system RPM higher than expected ON NO 2 CCM (See 01–02A–116 DTC P0507)
P0550 PSP switch circuit malfunction ON NO 2 CCM (See 01–02A–117 DTC P0550)
P0605 Internal control module read only memory(ROM) error OFF NO – Other (See 01–02A–118 DTC P0605)
P0703 Brake switch input malfunction ON NO 2 CCM (See 01–02A–118 DTC P0703)
P0704 Clutch switch input circuit malfunction ON NO 2 CCM (See 01–02A–120 DTC P0704)
P0705 Transmission range (TR) switch circuitmalfunction (short circuit)(See 05–02–11 DTC P0705)
P0706 Transmission range (TR) switch circuitmalfunction (open circuit)(See 05–02–14 DTC P0706)
P0715 Input/turbine speed sensor circuit malfunction (See 05–02–17 DTC P0715)
P0720 Output speed sensor circuit malfunction (See 05–02–19 DTC P0720)
P0725 Engine speed input circuit malfunction (See 05–02–21 DTC P0725)
P0741 Torque converter clutch (TCC) solenoid valvemalfunction (stuck off) (See 05–02–23 DTC P0741)
P0742 Torque converter clutch (TCC) solenoid valvemalfunction (stuck on) (See 05–02–25 DTC P0742)
P0743 Torque converter clutch (TCC) solenoid valvecircuit malfunction (See 05–02–26 DTC P0743)
P0751 Shift solenoid A malfunction (stuck off) (See 05–02–28 DTC P0751)
P0752 Shift solenoid A malfunction (stuck on) (See 05–02–30 DTC P0752)
P0753 Shift solenoid A circuit malfunction (See 05–02–32 DTC P0753)
P0756 Shift solenoid B malfunction (stuck off) (See 05–02–34 DTC P0756)
P0757 Shift solenoid B malfunction (stuck on) (See 05–02–35 DTC P0757)
P0758 Shift solenoid B circuit malfunction (See 05–02–37 DTC P0758)
P0850 Neutral switch input circuit malfunction (MT) ON NO 2 CCM (See 01–02A–122 DTC P0850)
P1449 CDCV open or short OFF NO – Other –(See 01–02A–124 DTC P1449)
P1450 EVAP control system malfunction (excessivevacuum) ON NO 2 CCM (See 01–02A–125 DTC P1450)
P1487 EGR boost sensor solenoid valve circuitmalfunction OFF NO – Other –(See 01–02A–127 DTC P1487)
P1496 EGR valve motor coil 1 open or short OFF NO – Other –(See 01–02A–128 DTC P1496)
P1497 EGR valve motor coil 2 open or short OFF NO – Other –(See 01–02A–130 DTC P1497)
P1498 EGR valve motor coil 3 open or short OFF NO – Other –(See 01–02A–132 DTC P1498)
P1499 EGR valve motor coil 4 open or short OFF NO – Other –(See 01–02A–134 DTC P1499)
P1512 VTCS malfunction (stuck close) ON NO 2 CCM (See 01–02A–136 DTC P1512)
P1518 VTCS malfunction (stuck open) ON NO 2 CCM (See 01–02A–138 DTC P1518)
P1562 PCM +BB voltage low ON NO 1 CCM (See 01–02A–140 DTC P1562)
P1569 VTCS solenoid valve circuit low input ON NO 2 CCM (See 01–02A–141 DTC P1569)
P1570 VTCS solenoid valve circuit high input ON NO 2 CCM (See 01–02A–143 DTC P1570)
P1601 Communication line error (PCM–TCM) ON NO 1 CCM (See 01–02A–145 DTC P1601)
P1602 Immobilizer unit-PCM communication error OFF NO – Other (See 01–02A–147 DTC P1602)
P1603 Key ID number unregistered in PCM OFF NO – Other (See 01–02A–149 DTC P1603)
P1604 Code word unregistered in PCM OFF NO – Other (See 01–02A–150 DTC P1604)
P1608 PCM internal circuit malfunction OFF NO – Other –(See 01–02A–150 DTC P1608)
P1621 Code word mismatch after engine cranking OFF NO – Other (See 01–02A–151 DTC P1621)
P1622 Key ID number mismatch OFF NO – Other (See 01–02A–152 DTC P1622)
P1623 Code word or key ID number read/write error inPCM OFF NO – Other (See 01–02A–152 DTC P1623)
P1624 Immobilizer system communication counter=0 OFF NO – Other (See 01–02A–153 DTC P1624)
P1631 Generator output voltage signal no electricity OFF NO – Other (See 01–02A–153 DTC P1631)
P1633 Battery overcharge OFF NO – Other (See 01–02A–155 DTC P1633)
P1634 Generator terminal B circuit open OFF NO – Other (See 01–02A–156 DTC P1634)

You could be on to something. A new knock sensor was fitted to our 2001 Astina when we owned it. The sensor had age detiorated and was probably falsely detecting knock and causing the car to feel "doughy". Huge improvement after fitting a new one.

JBT wrote:You could be on to something. A new knock sensor was fitted to our 2001 Astina when we owned it. The sensor had age detiorated and was probably falsely detecting knock and causing the car to feel "doughy". Huge improvement after fitting a new one.

Yeah mine was quite melted when the engine overheated, so it was suspect to start with. You can definitely feel the ignition being retarded dramatically.

In the mean time, as per the service manual I'll bypass the sensor with a 560k ohm resistor and see if it improves things.

In case you haven't ordered yet: 103USD genuine from Japan: http://www.amayama.com/search?q=JEB3-18-921A

Thanks for that! I'll have to do the maths on which works out cheaper with shipping and the other parts.

The service manual says the knock sensor should have a resistance of 560k ohm, so I plumbed in a 560k ohm resistor and took it for a drive. All the missing and hesitation is gone and the ignition isn't being retarded any more. I'd call that a win

So now I'll order the knock sensor and plumb that in, should fix it for good.

Great work/news Liam!

That amayama site is fantastic! It has most of the parts that I need for prices that are as cheap as the US, but it's all at 1 site. Now to see what they think shipping will cost.

Here's my awesome fake knock sensor;


My super effective fake knock sensor. by CaffeineAU, on Flickr

A bit of heatshrink and tape, and you can keep the fancy sensor as a spare!

Vat wrote:A bit of heatshrink and tape, and you can keep the fancy sensor as a spare!

Hehe I did put together one today with heatshrink, but I used the male spades instead of female, so I just knocked this one up tonight.

Caffeine wrote:That amayama site is fantastic! It has most of the parts that I need for prices that are as cheap as the US, but it's all at 1 site. Now to see what they think shipping will cost.

Rolley put me onto it a few weeks ago. viewtopic.php?f=18&t=67144&start=15

I'm trying it out this week for the first time. I'm finding prices about 50% below mx5parts and 75% below Mazda for genuine Jap parts. Rolley's search method is pretty good too, with the Arlington parts look-up, though I've found it easier if I start with a copy of the Mazda parts catalogue from miata.net.

Oh wow!

Their shipping quote for the knock sensor, a replacement harmonic balancer hub, new woodruff key, a few miscellaneous bolts and globes, is $12! (AUD)

That is spectacular and puts them well ahead of the US prices (Around $35 to $50 USD shipping)

Only issue is the harmonic balancer hub is delayed until April 15, but that's no big issue.

The only problem I've found with Amayama is the shipping can be a bit slow sometimes. But for the prices they've been charging me for shipping I don't mind waiting.