How To: H23A/H22/F20B Temperature Gauge for 2000-2002 models

bavarianblessed

Active Member
Joined
Oct 7, 2017
Posts
36
Reaction score
9
Location
Chattanooga
This seems to be a commonly asked question so I thought I would write up what I've learned

The 00'-02' model F23A Accords use a different circuit and gauge type for the temperature gauge in the cluster. For whatever reason, Honda decided that the ECU should be responsible for driving the temp gauge with a digital signal instead of the previous and much simpler method of a direct connection to the single-pin thermo sensor (part 37750-PH2-014) mounted to the side of the head. The 00'-02' model F23's have a bolt in this spot to seal the hole instead. If you are swapping in an F20B or H motor you'll need to work around this change if you want to use stock temp gauge.

**You will need to get a 98' or 99' gauge cluster**
I pulled one at my local LKQ for $30​

This is my setup:
  • 02' Accord SE Auto - F23A1
  • 01' PDE H23A with MCJA tranny
  • PCF ECU - OBD2b using the original F23A1 harness
So I'm swapping in a complete SiR Wagon (2WD) drive train and staying OBD2b for emissions compliance.


The F23A1 uses a VTEC pressure signal switch located next to the VTEC solenoid and the 2-pin water temp sensor on the side of the head here
dJB-UDiDmfRZHjlGs8UmjJTc7Z1dr0bZxmN9D9beCM5Ct-f7M_nzaZ_wook7XO4OtQVC2YA1lyGGG0Hi811OP-PRGnUkMMwm-acHB6FBhZxxW1TfSQwpwK708_utmu9BtFCJs86e7PKKg8Vz3FwMPQfnUcvevRKuTnqZl5ZZ3y2tmzVXYHG-3NBqSAv54L6PDgNUdKphOJJ-03xv-6O1NttYW9b4WYuZVSvh7pqKMXrQk5i7NeCxSowLsJEqN04rcfiigFmW46MdMmM-sPQ4XnWulkYKZ-0oNMh32BrSnQ9etlaIf7zJyIrwXGDCApxDs1nGUqqBbeggd-HtmP6J28lqF99grOglFOGiwMV3hUuk9pdkFEl0kCbwwzvuDDx0yJD3LNtja4YQMoW9MNkCcnydEbb9ucS-VJrpythIlE_zWJLu5xusmdGfO6hIdzRIBuHEMMgKux8qfMYbn7I1EvIafRG0MjBlyfq1nvyLW4zZdPgNGVh0BxWuJEpBNd7Z6XZRgCxE5lH6WkbxfBSNuAXGt1vBYh_t5f1jQaUA0eavG080ndnOsgILeUpOUBccNOKXn81DNIVaxa9oAjOb_SdEukXUZNFI8MdAhKQrOAbA3lLsdmesXPMBgJeUeBTBtwdYcxc1lNzkxB43gc-0NbSTsp92cjtN=w1130-h938-no



Since the H23A doesn't use a pressure switch this plug isn't used and since it's also located right next to the thermo sensor I clipped the connector off. You have a Blue/Blk and Brown/Blk wire there now, tape off the Brown/Blk wire, it's the sensor ground signal and not needed. The Blue/Blk wire is then soldered to the thermo sensor connector from the hacked H23 harness I got with my swap.
dQQofQfDjKmpkBSuZmecyJVdVKgN84eSqpJfJBZUsI8PlVS9rpSAIsDPHnSV_eHqHsYIIn_DGtBCDXUFytV9iUTUq2bOr5YJoRIHs01wIdJ5ZMjolL7Dw9A6dSRtE91pDeNac7CY20XGNIpfzjIBS5iGJSAqbBCQquor11-Z092ncWw09EUIRWeHcIXMFu_Wz-VzjQjDTd4uzIts005DNAbHnsnpwoH6PlKl4ywuGIz0jCyOFma1bbFhkesfc-fSpUwAWkakuZPRJYtLhat4Mp04GG9-bHCpjMcpDovlMf0XHIWXtnrosfGzykBqQRGgYWvVEvm2c6TlP6boacaswdyE2n86z0OM22tFSisvQt8DTK63alWisUVCwA40w6Hw0JIG-Fr9vsrG1AUGxdRcwhhYYEHJijwRgIL45SL6G37shXKsVx73cMhGZIR-xpy57JXWhNcQt3nbLjYZI-x0b9n7L0sCkm3BjiiF-Baxfgo2MAEVN7QjvyDgl_Zu3SQMsbB26pbBajUSkPg6w39eBo-n4ydlq8Pk0NqR9vmw3LWPtHzEKJSNuWL-DPOI-fzgUEdoEukvIFCkrN0Qpos3yxRxLE5YHu5Bwm5W_yZoly4g3rFbeMif3uUAYwBAneEjAD17DZxXh9IZ5OpPEbhdMg7AaLdfjMhL=w1103-h937-no



Once that was done I moved inside the car to finish the connection.
On the C connector at the ECU I de-pinned C10 and C24

C10 is the other end of that VTEC pressure switch that now has the thermo sensor connector on it
C24 is the coolant temp signal output from the original PAA ECU
fJJC3YK-6YRRJAg7OMGuQy4mPdTEZGTBEHg7EeGXASkXaV-U1CF5zTzQFRQfrLP-X2tgzgonmJMhCo4FiBNirPW7orRU9TWv686okRfa7g9_gtjhThhPzQuzeq2KF2PL-Z5hV2YVHZ8Alx0fT5kTfwLP8wG6nHNC4RruXiJtd-Syk-3NccGhTGmt94AaNovM46CSo7k8rJStn5Wxo2MTLoXz8J7Pk0MJAM4xvJaPW-sjqGokO2X4rBT9ktXPIGWPRaeW9oqXuG31bJ1lbhV9b1sZCx0RAGdjwC701TksaeYqmgFxNj3X2t_IhN72Gr1PrCG6Ov3UwU3znZtBFSQlpJy6qLj41nIB0p1fTW5mmqLLkHzI3Xa61Fhy1hqXJj9l3rR7drxgUeM4NPzHOQS7A9HpwsRVmRb-4gCOPPIL9EMPM_uoVESb8HtHdsw1XJdG2t8hnmusjXqut8i91Cp9Jav8teXCmUy8Kqgg-y_VMvewcazw1spu_5v5aCtvh6aSkFKMs-ZLrAbXeKHfzzwP6EY0i2HZ67Td6EZOaYOJpJmZyCEW235sk6B781qAplDak01efqg7ORFO-wP6kbk4DVydNt_qzN5t8rKdRm13v2eJs-RbHH6boMgzlrKLH4kmSZ92X8NGo4a2N4ydtCRPDc4dM4insZma=w1464-h822-no

Neither pin is used by the PCF ECU I'm installing and C24 will only have a wire in place on the 00'-02' models.
Once they are de-pinned clip the connector off each wire and strip the ends to twist and solder together
0L0rK-wwQtcLKi7yyrDwMVLxN0xedoPipw2bfo2hulgbi0Xxf-_4NiTNFdGSTJHa-tblMGqNrfoQVl8sp_hGu3KpDVjUS1z2wuopd1pF70IvzIa1SZUyWQ2wBBa48pjA-5UJSftJnQoX2lLe0xEAbJ0H5IlQHCGRQo4rQ5sKo_21wFcODBRsMK5SIRHuojPx64WyF8RUTR7-Tvvo7Vdp0KNMOOlG-5PL90KKcBoTefk5OwW8i1q0brXhYygmYfaH3tTQf5IMrKRnlPPa5tmVudmXaWAklJnI4UWY-zzozOsndlpL1eB_O5YDu-C4ab288PMp2kp9s-XHinizVcha6QhnM7zb4sN_Oby7UKVGgaXYBhnDs27v2dA-bW0OWwBA19k-XVChk1_rd6LtIJSB6RxrvkpE1PhDu4bKMsU7FvSoVKl1IeK9sivQcyF5yKTs7nmga7_GcPKJJSaptb2t5w3_P9XW71w9_00nVqcF9QA9jhGX957pVu9O8LP2VebSEAaUsqzViq1Yph1FIvvEnOyr5EZ1ybqF26Q45goFheiEIcPIDdPY-f4hZyRm4kv8dteNfkt6J_Fnwpz0OU7sPTfYYq1qCo7yoCRjowToIQh1tOIRB6AHI-UczuzZHfCUvZxJzZlkuJvHhUS8fEXWsOSQMCck5KkC=w921-h938-no


The other end of that Yellow/Grn wire from C24 connects directly to the gauge cluster on the cluster harness at pin C2
pr19JZxhvLE2oncQj9VpJEGTrdSV4DCsrH8OCi_ZLvu9eF4gbt-CgKFp7-rFb5OkEzE9m6WtsejdFMNgJecjZUsU7P7RvwBiMoJz1tGKfQsbk1-Fx6uW0aAvoFnMfEooyE5CjoxBoFCdAJbMcoS2cSPugj8BiWTjKvJSp5xSnHkqIkpQc22i1HuEtkKRf6Xp4RhJshxQEB9tEA9ao8ysgWCQuDQCfTK02x86hhxagUSPRprWx8fFA1BEO9U8LqKvGaePNBFkLt3Ug3z0FqeV86eS1pRAP3iFXjAFw3L3yUsWHrvMlRTD2pT5lM1C-eHJY8_3iW7qhwHYnFIRl_xU__yi8RchfkacU5d7MYwxpPFAjhR3Q705ZMdnNlWRSH9v0mCQqCQ_rIruK6Y5f12vWqYEUJRNDsvfKPK1VdSfHZG_aZGjrZLnZYuUwkwbqwWiiNOyJLkZeO3Map3OYcg7dQYYQMpL2mFIb-X-gtd6lo20oYCSCpRMJpvbWUdudBwzW8VuyF_gzq78R5CpViEWa-VDZRqjSBluWmsW3kmTSbSl2c6T1h76uQE_lo4jyXP3t2b8uL-mxh6DIPrsDjLf6xRbr_MnEppWCYG12x6E9oRgZa8JbmhZShyx3L4j4t-c_5mQeZ6HijwQqhuLQ15ktkIlfWecAbgc=w1624-h667-no


Once completed you will have a direct connection from the thermo sensor to your 98' or 99' gauge cluster. As long as you properly solder (and strain relief) or crimp your connections the circuit impedance will be negligible and shouldn't affect your temp readings at the gauge. I measured resistance between the thermo connector under the hood and C2 at the gauge harness and got this
phRy8t_Z8LliwqYygExdF7ktOtOaDkOYH-WWuGPnX9P2fnbjKjHCN2egH6GQAGtrCbB1Ab0JZV7Xp837-vz9gez2c8twL4MC2UGL8QTB7ktBelR18kdC17CDuW-YBvAe08Gp_M-vPxVu0qLHNN45wGHYj4-j3HUqpq3CffBiL8sg9XItA4qFdnXhLpEsecc_aQg5kL10Kv0E91PcM_4tD7tNkTUBlfSipUsz5xJOvcVwH9fd09cZIIdihBSU5iYKI-M7IuzubQtMgoqkhgMYR9BXQiFR88adplD05J1Ci1stXAXbur81syXNPJRXdvVKLvU_mi1PLJdsbCMXQwbvZT2ErxE9bqXqsMsRXWUK7DP88CAGQhDu_pYLyKw0-3t_W9YV8sgHDI5Ou-0FhP17QDNYMFFzugZZH-UFEHt7PexIOPEqe81ciwOhRevcFfPQbgL4tUDoXl1La8wCUyJJ99z7zKgjZF6mb4_EfjuadJ6ntTGMpPhSUXRP_9hQH8W6JOqMbOf7Jkn0-4hWv0dxhqdTStiKfnhZIfzKmodHGDVP7RBRvLiLznnKF8-4N_5jJU_zFBki4I0_Sa-EyqtgNTPF2qBBdQmMe9kIs_bFhao2ZkQV4hOAxRXlPMBXXQ73yXjMQ3ztjy5TYmUp-ztjbHJc-xmwlMlf=w719-h937-no



This is what I did to make it work and the info for the wiring and gauge cluster differences was obtained from a few different posts here and from studying the Helms manual so I'm not an expert. If anyone has questions though ask away, I'll try to help :beer:



 

Mark2001Accord

Well-Known Member
Joined
Apr 10, 2019
Posts
57
Reaction score
11
Location
Chicagoland
They work now.

Will replacing the cluster effect the immobilizer? The cluster displays the source mileage from the ECU, not the cluster, correct? I think that the odometer has to do with the immobilizer system and security, perhaps not. I cannot recall. Its been a while.
 

bavarianblessed

Active Member
Joined
Oct 7, 2017
Posts
36
Reaction score
9
Location
Chattanooga
They work now.

Will replacing the cluster effect the immobilizer? The cluster displays the source mileage from the ECU, not the cluster, correct? I think that the odometer has to do with the immobilizer system and security, perhaps not. I cannot recall. Its been a while.
No it won't mess with the immobilizer. The mileage and trip data are stored on a little pdip-8 eeprom chip on the cluster PCB. You can swap that chip to your new cluster to keep the mileage info with the car. I'll post some pics in a bit
 

bavarianblessed

Active Member
Joined
Oct 7, 2017
Posts
36
Reaction score
9
Location
Chattanooga
Sorry for the delay, I completely forgot about this.

Here is what I did to transfer the odometer info from my original cluster to the new one


Once you have the cluster apart locate the eprom chip on the PCB that contains the info. On the 99 cluster it's to the left of the LCD read out. I think it was above it on the 02, here is a pic of the location on the 99
IMG_20190810_022808.jpg

Close up
IMG_20190810_024029.jpg


Flip the board over and locate the pins of that chip. I used my Hakko FR-301 to de-solder and remove the chip but a copper braid solder wick will get the job done as well
IMG_20190810_024115.jpg
IMG_20190810_024224.jpg


Do the same thing on the other cluster PCB and remove the chip with the info you want transferred.
Here are both chips side by side, just to show that they used different vendors for the part so don't get hung up on looking for that specific part number
IMG_20190810_024344.jpg
 

bavarianblessed

Active Member
Joined
Oct 7, 2017
Posts
36
Reaction score
9
Location
Chattanooga
Solder the chip in place of the original one and your mileage info will be transferred to the new (older) cluster

IMG_20190810_024810.jpg
IMG_20190810_024835.jpg


Not much to it really, hit me up if you have any questions though.
 
Back
Top