Engine/Transmission (1994 - 1998) gauges don't work, won't go into gear

[robertsalverda]

hi guys, i've got a 98 12 valve. started it up the other day. all the gauges stayed pinned at zero. air cond. wasn't cold and when i tried to put it into gear it stalled. shut off and tried again. same thing. runs fine in " park" but won't shift. on the fourth or fifth try, the gauges fired up, the air started blowing cold ( and the fan picked up a bit of speed also) and was able to shift into drive without it stalling. i seem to recall a post a long time ago regarding the gauges not working and some kind of sensor switch regarding torque convertor or transmission. does anyone know what the problem might be???? thanks rob

 

[Dave M]

I had a similar problem with my 97 5spd. The problem was the Crank Position Sensor (CPS) or sometimes called the Engine Speed Sensor (ESS). On my 97 the ESS is monted on the block 0. 050 inches above the crank damper/balancer. Cost about $70 from NAPA.



Here was my thread on on it:



https://www.turbodieselregister.com...ons/184945-electrical-woes-maybe-bad-pcm.html



MY gage lights that didn't come on for the bulb check were:



Water in fuel

MIL

GEN

Airbag



Also the Alternator did not charge, Tach dead, Speedometer dead, AC dead but blower worked.



The Oil pressure gage, water temp gage, voltmeter, fuel gage, headlights and turn signals all worked. The ABS light , oil pressure light, seatbelt light, Brake light, blinker arrows, headlight ind, are all gage indicator lights that worked.



I disconnected the bad crank sensor and all the gage lights came on with the bulb check. Double check the air gap between the harmonic balancer, and the ESS Stick a piece of cardboard (like from a cereal box, dont use corrugaged, wayy too thick) or business card between the balancer, and sensor, push down, the magnet will hold the sensor to the balancer, tighten the nuts, and remove the cardborad.



The ESS supplies a tach signal to the PCM to get things going. If the ESS is bad then all those functions won't work. Since yours is an auto it may control the transmission functions too.



Dave

 

[Dave M]

Heres another similar thread to yours in the 911 forum:



https://www.turbodieselregister.com...3422-no-tach-not-charging-irratic-lockup.html

 

[robertsalverda]

thanks dave, that sounds exactly like the solution to my problem. and it all makes sense when you read the other thread in the 911 forum. i'll be napa bound first thing in the morning. thanks again, rob

 

[Dave M]

Before you replace it unplug it turn ignition key to on and see if some of your bulb check lights come on like MIL, etc. There is about a 2 foot pigtail on the wires from the ESS that snake its way up the front left of center of the engine and end in a 3 pin connector to the left (drivers side of top of engine). Unplug it and turn your key on to check the gage check lights on dash. If they now come on you may have a bad ESS but it could be a wiring issue or the PCM itself is bad.



Note: I believe 24v engines had the ESS back by the starter and they had 2 computers (ECM and PCM).



The 3 pins on my ESS pigtail connector were (1) 5 volts from the PCM to power the ESS and (2) GND and (3) was the pulse output of the ESS back to the PCM which you need a freq meter or special test equip to check. That's why most people just replace it and go on. Some vehicles had 12v or 8 volts instead of 5 but check it with key on. Also check for bad connections/wiring at the connector on the 3 plugs on the PCM. To do that I would disconnect both battery GND post first.



It sounds like it could be the ESS but it still could be wires/connections or PCM or wrong gap on ESS. The . 050 is not too critical. A business card will do but since the senser is magnetic you can't use a feeler gage unless its bronze.



When I had these problems I didn't know about the ESS and how it functions and after much troubleshooting figured it was the PCM. After replacing it with a $500 PCM I then learned about the ESS or CPS. Hope I can save others from replacing a good PCM.



Good Luck

 

[robertsalverda]

thanks again, replaced the ESS and it did the trick.

 

[Dave M]

thanks again, replaced the ESS and it did the trick.

Great! I spent days figuring it out when mine failed. It was a relatively simple fix for you. Glad we could help.