Codes 22, 24, 41 & 47

[Zuffen]

Just so I don't get bored my car decided to throw a few codes at me.

22 Water temp sensor
24 Air intake temp sensor
41 TPS
47 Secondary TPS

I can ignore 47 as I don't have a traction Control engine so that's easy.

22 & 24 are interesting as I've checked the sensors and both are within range of the workshop manual.

I've checked continuity to the ECU and to the chassis and all read good.

I also have voltage where it should be.

41 the TPS is an easy fix and I just need to adjust it but the car idles at 650rpm so it can't be too far out.

The car runs with a slight stumble below 2,000rpm but gets up and starts to go well at 3,000rpm and is going very hard above 4,000.

I've tried swapping the AFM/MAF to no effect. I've checked the contacts on the sensors and the ECU and they look clean.

At this point I'm starting to run out of ideas, so any suggestions would be most appreciated.

 

[cribbj]

Rod, is this the ECU you replaced the caps on a few months ago? Perhaps swap in another ECU?

 

[George_R]

Trace E2 circuit from ECU pin to the sensors you just mentioned. Check continuity first. Maybe ECU pin got loose

 

[gloverman]

Check the connection of pin 65. All of those sensors share that common earth.

 

[Zuffen]

To respond in order,

John,

The caps were replaced professionally and I have absolute faith in the job.

George/Kelvin,

I've got a zero resistance reading on the brown wire at the AIT sensor to the engine block. This would mean I have continuity through pin 65 to ground.

Am I assuming too much on the continuity front?

The car doesn't have the CEL illuminated when running but the light does come on with ignition (not flashing) as it is supposed to. I'm getting my codes with the engine running and/or just ignition on.

Thanks for the help to date.

 

[George_R]

I would suggest some test:
1 disconnect TPS
2 put some resistor between VC and E2 at TPS connector (1kOhm 0.25Wt would be ok, real TPS is ok too)
3 ignition on
4 use your multimeter and see if there's any voltage between E2 pin of the TPS connector and engine block
shuffle your loom around ECU and see if there's any voltage coming on sometimes

 

[cribbj]

Rod, I was thinking perhaps there are other issues with that ECU that may not have come to the surface, and possibly the new caps themselves may not have been the best quality? You're going into your hot season now and that's when electronics suffer.

 

[Zuffen]

I'm off to visit my Mum for a few days (only a 10 hour drive!) so wont get back onto it until Friday at the earliest.

I know the caps job was done right, but there could be other problems in the ECU, you never know.

 

[Zuffen]

George.

Did the resistor test and no voltage present at E2.

I also checked the voltage at the sensors and here's what I got.

Note this was with the ignition on and both plugs unplugged from their sensors.

AFM:

Pin 4 VC 5 volts
Pin 5 good ground return
Pin 3 KS 5 volts
Pin 2 THA 5 volts
Pin 1 E2 good ground return

TPS

Pin 1 E2 Good ground return
Pin 2 IDL1 12 volts
Pin 3 VTA1 5 volts
Pin 4 VC 5 volts

I was surprised to see 5 volts on Pin 3 & 4 of the TPS.

It took a while to do as Christmas meant too much red wine to go climbing into the engine bay!

Over to the experts!

 

[George_R]

Vodka fumes prevent me from answering this topic, so I'm backing off for a while )

Overall, I was surprised that the resistor test didn't show weak connection of E2 circuit (all the way from ECU to sensors). Maybe there's problem inside ECU then. Like some discontinuity between E2 and E1.

Observing 5v at resistive sensors' inputs doesn't sound bad to me. Must be weak pullups / some feature of input circuit.