what are the "h" codes?
Thread Starter
Racer
Joined: Feb 2002
Posts: 455
Likes: 0
From: Fraser MI
what are the "h" codes?
i was out test driving my car tonight, all of a sudden the check engine light came on, and the car started running MUCH better :confused:
what are codes H23 and H84? I found a code 23 at a site that said it is the IAT sensor...could that make the car run poorly? i have no idea what the H84 is though...
thanks in advance
:cheers: :cheers:
what are codes H23 and H84? I found a code 23 at a site that said it is the IAT sensor...could that make the car run poorly? i have no idea what the H84 is though...
thanks in advance
:cheers: :cheers:
Intermediate
Joined: Sep 2002
Posts: 28
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From: Cair Paravel Rhindon
Re: what are the "h" codes? (konroh)
The H just stands for "Historical". It's a stored code. "C" is for "Current".
What library/module were you in? Is the '84' in module 1, 4, 7, 9, or A? 1 is ECM, 4 is PCM, 7 is Realtime Dampening (RTD), 9 is ABS/ASR, and A is DERM(Airbag).
http://www.corvettedoctor.com/1994-96_Codes.htm
DTC #23: Intake Temperature Sensor Circuit Voltage High.
Code 84 is in your transmission.
DTC #84: 3-2 Control Solenoid Circuit.(Automatic only)
DTC #84: 2nd and 3rd Gear Blockout Relay Control Circuit.
Hmm...do you have a manual transmission with the CAGS defeat installed?
~Paladin
[Modified by The Paladin, 10:35 PM 10/6/2002]
What library/module were you in? Is the '84' in module 1, 4, 7, 9, or A? 1 is ECM, 4 is PCM, 7 is Realtime Dampening (RTD), 9 is ABS/ASR, and A is DERM(Airbag).
http://www.corvettedoctor.com/1994-96_Codes.htm
DTC #23: Intake Temperature Sensor Circuit Voltage High.
Code 84 is in your transmission.
DTC #84: 3-2 Control Solenoid Circuit.(Automatic only)
DTC #84: 2nd and 3rd Gear Blockout Relay Control Circuit.
Hmm...do you have a manual transmission with the CAGS defeat installed?
~Paladin
[Modified by The Paladin, 10:35 PM 10/6/2002]
Thread Starter
Racer
Joined: Feb 2002
Posts: 455
Likes: 0
From: Fraser MI
Re: what are the "h" codes? (The Paladin)
Both codes were in module 4. I do have no CAGS so I guess i can ignore code 84. What symptoms would that code 23 cause? after the check engine light came on, my hesitation off the line went away :confused:
I am wondering if all this time i just have a bad IAT sensor!!
I am wondering if all this time i just have a bad IAT sensor!!
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
Re: what are the "h" codes? (The Paladin)
:cool: I've been looking for a comprehensive list of 94 - 96 codes :cool:
Intermediate
Joined: Sep 2002
Posts: 28
Likes: 0
From: Cair Paravel Rhindon
Re: what are the "h" codes? (Lone Ranger)
No data received from the IAT sensor forces your car into its 'best guess' mode. That will only improve your performance if its 'best guess' matches current conditions exactly.
However, if your IAT was functional but providing erroneous information, a reversion to 'best guess' mode might improve performance.
From the service manual -
- Basically, the ECM sees the IAT sensor reporting -38 degrees, and the ECT sensor saying it just isn't so - the IAT sensor must be insane!
A DTC 23 will set due to an open sensor, wire, or connection. It is either a bad sensor, a bad wire, a bad connection, or a bad ECM. Wiggle some wires, good sir.
[Modified by The Paladin, 7:12 PM 10/7/2002]
However, if your IAT was functional but providing erroneous information, a reversion to 'best guess' mode might improve performance.
From the service manual -
DTC 23 will set if:
o A signal voltage indicates an IAT below -38 deg. F
o Engine coolant temp above 85 deg. F
o Engine idling (0% throttle)
o No VSS signal (vehicle not moving)
o All conditions met for 60 seconds.
o A signal voltage indicates an IAT below -38 deg. F
o Engine coolant temp above 85 deg. F
o Engine idling (0% throttle)
o No VSS signal (vehicle not moving)
o All conditions met for 60 seconds.
A DTC 23 will set due to an open sensor, wire, or connection. It is either a bad sensor, a bad wire, a bad connection, or a bad ECM. Wiggle some wires, good sir.
[Modified by The Paladin, 7:12 PM 10/7/2002]
