Unable to start Key On Engine Running test

[iheart2code]

Hello everyone!

I have recently purchased a 1993 Ford Ranger STX 4.0L long bed with manual transmission, and am trying to get it into good running condition. I have been able to successfully pass a Key On Engine Off test, but when I try to perform an engine running test, the test does not start.

This is my first experience working with a vehicle with pre-OBD computer, so I'd appreciate some guidance here.

Thanks!

 

[RonD]

Welcome to TRS

You have a 1993 Ranger and they use 3 digit OBD1 codes, not 2 digit

Warm up the engine
shut it off

Put computer into Self Test using the jumper on the OBD1 connector in engine bay
Start engine
CEL should flash 3 times indicating a 6cyl engine
Then wait, takes a good 30-60 seconds, engine RPMs may go up and down or rough running while waiting, computer is testing things
There will be 1 Flash
Turn steering wheel left 1/4 turn, then right 1/4 turn then straight
Press brake pedal once then press gas pedal down to REV engine once
Called the goose test
Wait
If there are any codes CEL should start flashing them
And it will repeat them once

111 code means all is well


3 digit code list here: https://www.therangerstation.com/tech/obd-i-diagnostic-trouble-code-dtc-applications-ford-3-digit-codes/

 

[iheart2code]

Thanks for the reply, RonD.

I have an OBD1 reader for the car, which I am using as per the instructions. I am not currently seeing the cylinder code flash while attempting an engine running test.

 

[RonD]

Never tried with a Reader

Try using a wire or paper clip between self test IN and Signal Reurn slots

Slots seen here: https://www.ford-trucks.com/forums/attachment.php?attachmentid=271754&stc=1&d=1625151146

Engine warm
Key off
Install jumper wire
Start engine watch CEL

 

[iheart2code]

So, I am getting a code during the KOEO test: 522 - vehicle not in park or neutral during KOEO. Would this prevent the engine running test from starting?

I have a post about a "dangling connector" that I am wondering if is related to park/neutral not being detected: https://www.therangerstation.com/forums/index.php?threads/help-identify-this-dangling-connector-on-1993-ranger.207664/

 

[iheart2code]

It's worth noting that I am also seeing a code 528: clutch switch circuit fault. On the manual transmission models, does the clutch switch also indicate neutral/park status?

 

[RonD]

All Rangers up to 2002 were wired for Manual transmissions
If an automatic was installed an extra wiring harness was added

Under the dash where a clutch pedal would be is a long 6 pin connector for a clutch switch, at the factory they would plug in an extra harness to that switch connector and it extend the wires thru the firewall and down to the automatic's NSS(neutral safety switch), on drivers side, plunger type switch, with round 4 or 5 wire connector, above shift rod
This is also the Reverse Light switch

NSS looks like this on an A4LD automatic: https://www.infinitybox.com/wp-content/uploads/2021/02/AOD_Neutral_Safety.gif

 

[iheart2code]

The truck does have a manual transmission. I am mostly wondering if the clutch position sensor is bad, could this generate a code 522 (vehicle not in park or neutral during KOEO)?

 

[RonD]

Yes, it would if clutch pedal was not pushed down all the way

 

[iheart2code]

Do I need to have the clutch pedal pressed during the tests? The instructions I've seen only indicate the pedal needs to be pressed if you have the 4.9L engine, which I do not.

 

[RonD]

Pedal down is "neutral" with a manual trans, so if it mentions "neutral" that means pedal down

 

[iheart2code]

Ok, I'll replace that faulty clutch position sensor and then report back. Hopefully that fixes things. Thanks!

 

[iheart2code]

Replaced the faulty clutch position sensor did indeed resolve this issue. I am able to perform the engine running test now. Thanks for the help!