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Discussion Starter #1
i got 2 manufacture specific codes on my friends auto x-ray scanner when scanning my pick up truck. they are P1100 and P700 anyone know what they are? the scanner cant tell me because they are maufacture specific codes and the scanner will only read under a generic setting because its a 95 S10
4x4 vortec (W) vin vehicle... it also showec the timing jumping around all over the place with negative (minus sign) in front of the number. anyone know? thanks so much
 

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Those look like OBDII codes...wasn't the '95 model year the transition/cut off from OBDI to OBDII coding (a service tech would better know that than me)? But, I believe the P1100 codes tend to be an intake manifold sensor failure (e.g., MAP or IAT, etc.). I think the P0700 codes are transmission related. I would suggest having the codes read and confirmed. Good luck.
 

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map or maf sensor, depending which you have

transmission control system malfunction

that is what i got from my 5min search
 

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67 4 door, 65 wagon (in pieces)
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Some 95 gasoline vehicles were OBDII accoriding to my scanner instructions.

P0700 = Trans Control Sys Malfunction

P1100 = my codes only go up to P0999, sorry
 

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+1 on the P0700. Try checking the fuses or loose connections and then reset the code. If it comes back my book says its dealership time.

I have the GM specific codes and I don't have a P1100. the P11XX codes are mostly intake and fuel related.
 

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Discussion Starter #6
i forgot to mention that the truck saysOBD 1 certified on the emissions sticker under the hood. and the plug undr the dash is a 16 pin trapoziod shape... how can i be sure that P1100 is a MAP sensor? also if the MAP Sensor is bad, how would the engine run? like what problems would it cause? any help is greatly appreciated
thanks
 

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i forgot to mention that the truck saysOBD 1 certified on the emissions sticker under the hood. and the plug undr the dash is a 16 pin trapoziod shape... how can i be sure that P1100 is a MAP sensor? also if the MAP Sensor is bad, how would the engine run? like what problems would it cause? any help is greatly appreciated
thanks
What problems/symptoms are you experiencing?
Chances are your 95 is a speed density setup. So MAF is likely outta the question. Look for a vacuum leak!! That's the most common problem.:yes: Second most common is a bad TPS which will cause all sorts of weird codes with the engine AND transmission because the ECM can't figure out why the engine is getting too much/not enough air for the amount of throttle position and the tranny can even start shifting all weird. It also effects the lock-up function in the converter.
 

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Discussion Starter #8
What problems/symptoms are you experiencing?
Chances are your 95 is a speed density setup. So MAF is likely outta the question. Look for a vacuum leak!! That's the most common problem.:yes: Second most common is a bad TPS which will cause all sorts of weird codes with the engine AND transmission because the ECM can't figure out why the engine is getting too much/not enough air for the amount of throttle position and the tranny can even start shifting all weird. It also effects the lock-up function in the converter.
im experiencing rough idling and rough running between 1000 RPM and 2000 RPM with a very noticeable misfire. also when i hook up a scanner under the dash, the timg reads in the negative range and the timing numbers are all over the place. jumping around anywhere from -34 to -8 to -20 to -0 to -24 ect. jumping around really fast. the truck is a 95 S10 4x4 vortec engine with a W in the vin. and has 60k on the body and 20k miles on the motor. the dealer put in a new long block about 3 years ago when my father had the truck.... the P1100 and P700 are pending codes that i found when i put the scanner on it. thanks so much
 

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FIRST...... Check the cap/rotor, plug wires and plugs!! Many mysterious problems are found there!! That was the first year of the Mass-air Vortec engine so some trucks have it and some don't. Follow the air inlet duct from the air filter assembly and see if it's got the Mass-air (MAF) sensor. BEFORE you go buying another MAF, MAKE SURE you don't have any vacuum leaks because that will cause the SAME symptoms and trouble code!! Basically unmetered air entering the system. Common trouble areas are around the EGR and on the little plastic vacuum lines running into the cab for the A/C controls.

Get a good service manual. It will list what the output voltages should be from the MAF so you can check it that way also.
 

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Discussion Starter #10
FIRST...... Check the cap/rotor, plug wires and plugs!! Many mysterious problems are found there!! That was the first year of the Mass-air Vortec engine so some trucks have it and some don't. Follow the air inlet duct from the air filter assembly and see if it's got the Mass-air (MAF) sensor. BEFORE you go buying another MAF, MAKE SURE you don't have any vacuum leaks because that will cause the SAME symptoms and trouble code!! Basically unmetered air entering the system. Common trouble areas are around the EGR and on the little plastic vacuum lines running into the cab for the A/C controls.

Get a good service manual. It will list what the output voltages should be from the MAF so you can check it that way also.
i followed the duct and it doesnt have a mass air sensor.... only a air inlet temperature sensor....i will check the rotor again for play. also whats a good service manual? helm? chilton?
 

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If your truck is OBD 1 certified then the codes you are retrieving are likely bogus. Is there a connector that looks like this?:

12 Pin ALDL


Turn ignition switch to OFF position
Locate the Assembly Line Data Link (ALDL), see image above.
Jumper the A&B terminals(a paper clip or a jumper wire work ok)
Turn Ignition switch to ON position.
Count the flashes on the "CHECK ENGINE" or "SERVICE ENGINE" light.
FLASH, pause, FLASH, FLASH = code 12
NOTE: Some 94 & 95 models do not have the B terminal. In which case a scanner is required.
NOTE: Some 94 & 95 models that DO have the A & B terminals still require a scanner.

A - Ground
B - Test Terminal
C - Air Injection
E - Serial Data
F - TCC
G - Fuel Pump
H - Brake Sense Speed Input
M - Serial Data



Clearing Trouble Codes
Diagnostic trouble codes may be cleared by disconnecting the battery ground cable for at least 20 seconds. Reconnect negative battery cable and recheck codes to confirm the repair. OBDII can also be reset with a scanner.




OBDI Codes

4.3L VIN Z and W


12 – Diagnostic mode

13 - Oxygen sensor circuit - Oxygen sensor voltage stays between 0.35 and 0.55 volts for 30 seconds when the TPS signal was above 0.55 volts. The engine had been running for at least 40 seconds with an engine temperature above 110? F.

14 - Coolant temperature sensor or circuit/ high temperature indicated - Coolant temperature sensor signal indicates a temperature of over 284? F for 4 seconds after the engine had been running for at least 10 seconds.

15 - Coolant temperature sensor or circuit/ low temperature indicated - Coolant temperature sensor signal indicates a temperature colder than -36? F for at least 4 seconds after the engine had been running for 2 seconds.

16 – System voltage high - Charging system voltage was either below 9 volts or above 17 volts for 10 seconds.

17 – Crank Signal Circuit - PCM did not detect any spark reference pulses within 240 fuel control reference pulses (80 crank revolutions) while engine was running below 1200 RPM.

19 – Crankshaft Position Sensor or circuit

21 – Throttle Position Sensor TPS or circuit voltage high - TPS voltage was above 0.8 volts for 5 seconds when engine was running and air flow was less than 15 gm /sec, or the TPS voltage was over 4.8 volts at any time.

22 – Throttle Position Sensor TPS or circuit voltage low - TPS voltage was under 0.2 volts for 4 seconds when the ignition was on.

23 – Intake Air Temperature (IAT) sensor circuit – low temperature indicated - Inlet air temperature sensor signal showed an air temperature of -29? F for 4 seconds.

24 - Vehicle Speed sensor circuit - Vehicle speed sensor signal showed less than 3 MPH for 2 seconds when engine speed was greater than 3000 RPM and transmission has not been in park or neutral for more than 4 seconds. Or vehicle speed goes from above 18 MPH to 0 in less than 2 seconds without applying brake.

25 – Intake Air Temperature (IAT) sensor or circuit – high temperature indicated - Inlet air temperature sensor signal showed an air temperature of over 218? F for 5 seconds when vehicle speed was greater than 35 MPH.

26 - Quad-Driver sense voltage shows a low voltage when battery voltage should be present, or if the sense voltage shows battery voltage when a low voltage should be present for at least 5 seconds when the engine was running.

27 - 2nd gear switch was closed or grounded for 10 seconds when vehicle was in 4th gear, or 2nd or 4th gear switch was open when engine was first started.

28 - 3rd gear switch was closed or grounded for 10 seconds when vehicle was in 4th gear, or 3rd or 4th gear switch was open when engine was first started.

29 - 4th gear switch was closed or grounded for 10 seconds when vehicle was in 4th gear, or 4th gear switch was open when engine was first started.

31 - Park/Neutral Position (PNP) switch circuit - PRNDL indicates a gear other than park or neutral for 13 seconds for 3 consecutive startups when ignition was on, engine was off and vehicle speed was 0. Or the PRNDL status indicators (A, B, C, P) showed an incorrect combination of Lo and Hi for more than 10 seconds.

32 - Exhaust Gas Recirculation (EGR) Circuit - EGR open command did not change the fuel mixture when the command was given during off idle operation. EGR opening should cause the mixture to be slightly richer because of the low oxygen content of exhaust gas.

33 - MAP sensor signal voltage was too high (low vacuum) for 5 seconds when throttle opening was under 2%.

34 - MAP sensor signal voltage low - MAP sensor signal voltage was too low (high vacuum) when engine speed was over 1200 RPM, or the throttle angle was above 21% when engine speed was over 1200 RPM.

35 - Idle Air Control (IAC) System

38 – Brake Switch

41 – Camshaft Sensor Circuit

42 – Bypass or Electronic Spark Timing circuit - The EST signal did not change when the ECM applied bypass voltage to the ignition module.

43 – Knock Sensor Ciruit - Knock sensor signal was either above 3.5 volts or below 1.5 volts for at least 20 seconds.

44 - Oxygen sensor or circuit – lean exhaust detected. - Oxygen sensor voltage was under 0.25 volts for up to 4 1/2 minutes of closed loop operation.

45 - Oxygen sensor or circuit - rich exhaust detected. - Oxygen sensor voltage was over 0.750 volts for 2 minutes in closed loop operation with a throttle angle between 0.6 and 1.9 volts.

46 – Power Steering Pressure Switch circuit

47 - Momentary loss of power to Body Computer Module (BCM).

48 – Misfire Diagnosis

51 - MEM-CAL, PROM, or ECM Error (Faulty or Incorrect Calibration)

52 – CALPAK or ECM problem

53 – System over-voltage – ECM over 17.7 volts

54 – Fuel Pump Circuit

55 - ECM problem
 
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