bert01xj
NAXJA Forum User
- Location
- souderton,pa
99 cherokee 4.0 aw4 jeep runs fine just keeps showing cel p1698 P1494 p1694. I am not home or I would search. I have a full 99 parts jeep.
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three codes is my computer going?
- Thread starter bert01xj
- Start date
Digger87xj
NAXJA Forum User
- Location
- Buffalo Creek/Lakewood CO
p1698 no ccd messages from TCM to PCM
p1494 leak detection pump switch or mechanical failure (emissions)
p1694 no ccd messages from PCM to TCM
There's a communication problem between the PCM and the TCM short or open in the CCD bus
There's a fault with the LDP,
Could be a related harness problem with all 3 codes... I've seen mice cause problems chewing on wires under the hood.
p1494 leak detection pump switch or mechanical failure (emissions)
p1694 no ccd messages from PCM to TCM
There's a communication problem between the PCM and the TCM short or open in the CCD bus
There's a fault with the LDP,
Could be a related harness problem with all 3 codes... I've seen mice cause problems chewing on wires under the hood.
- Location
- Minneapolis, MN
I suggest testing the CPS and inspecting the CPS wire harness/wire plug for damage or corrosion. Read the 
thread and the Wiki.
http://www.naxja.org/forum/showthread.php?t=63167
http://wiki.answers.com/Q/What_does_code_p1694_mean_for_a_2000_Jeep_Cherokee
P1694 Fault In Companion Module. No CCD/J1850 bus messages received at the power train control module (PCM) from the AisinWarner Transmission Control Module (TCM).
P1694 will set if no CCd bus messages are received from PCM for 20 seconds or invalid messages are received for 20 seconds.
Possible Causes
-CCD Bus (-) circuit open between PCM and TCM.
-CCD Bus (+) circuit open between PCM and TCM.
-Transmission CCD bus wiring damaged.
-Faulty TCM
P1698 No CCD Messages Received From PCM. Bus communication failure to PCM. A "Companion DTC" was set in both the ECM and PCM.
Possible Causes:
- Faulty Engine control Module (ECM)
- Engine control Module(ECM) harness is open or shorted
- Engine control Module (ECM) circuit poor electrical connection
When the CPS short circuits the engine computer (PCM) shuts down to prevent damage to itself. As a result, there is no communication (P1694).
Disconnect your crankshaft position sensor then put the ignition key in the on position. If the instrument cluster starts to work once the CPS is disconnected, then you know the CPS or CPs wires are shorted. You can verify this by testing the CPS and checking continuity on the CPS wires.
P1694 Diagnostic Procedure
1. Using scan tool, clear TCM DTCs. Start engine and let idle for at least 2 minutes. Using scan tool, retrieve TCM DTCs. If DTC P1694 returns, go to next step. If DTC P1694 does not return, go to step 5.
2. Check instrument cluster gauges for proper operation. If fuel gauge and speedometer operate properly, go to next step. If fuel gauge and speedometer do not operate properly, see appropriate INSTRUMENT PANELS article.
3. Turn ignition off. Disconnect Gray PCM harness connector. PCM is located at left front of engine compartment. Disconnect TCM harness connector. Measure resistance of CCD BUS (-) circuit (White/Black wire) between TCM harness connector and Gray PCM harness connector. If resistance is more than 5 ohms, repair open in CCd BUS (-) circuit (White/Black wire). If resistance is 5 ohms or less, go to next step.
4. Measure resistance of CCD BUS (+) circuit (Violet/Brown wire) between TCM harness connector and Gray PCM harness connector. If resistance is more than 5 ohms, repair open in CCd BUS (+) circuit (Violet/Brown wire). If resistance is 5 ohms or less, replace TCM.
5. Conditions necessary to set DTC P1694 are currently not present. Inspect related wiring and harness connectors. See WIRING DIAGRAMS. Repair as necessary. If no problem is found, check for broken, bent, backed-out or corroded terminal pins. Check for chafed, pierced or partially broken wires inside insulation. Repair as necessary.
thread and the Wiki.http://www.naxja.org/forum/showthread.php?t=63167
http://wiki.answers.com/Q/What_does_code_p1694_mean_for_a_2000_Jeep_Cherokee
P1694 Fault In Companion Module. No CCD/J1850 bus messages received at the power train control module (PCM) from the AisinWarner Transmission Control Module (TCM).
P1694 will set if no CCd bus messages are received from PCM for 20 seconds or invalid messages are received for 20 seconds.
Possible Causes
-CCD Bus (-) circuit open between PCM and TCM.
-CCD Bus (+) circuit open between PCM and TCM.
-Transmission CCD bus wiring damaged.
-Faulty TCM
P1698 No CCD Messages Received From PCM. Bus communication failure to PCM. A "Companion DTC" was set in both the ECM and PCM.
Possible Causes:
- Faulty Engine control Module (ECM)
- Engine control Module(ECM) harness is open or shorted
- Engine control Module (ECM) circuit poor electrical connection
When the CPS short circuits the engine computer (PCM) shuts down to prevent damage to itself. As a result, there is no communication (P1694).
Disconnect your crankshaft position sensor then put the ignition key in the on position. If the instrument cluster starts to work once the CPS is disconnected, then you know the CPS or CPs wires are shorted. You can verify this by testing the CPS and checking continuity on the CPS wires.
P1694 Diagnostic Procedure
1. Using scan tool, clear TCM DTCs. Start engine and let idle for at least 2 minutes. Using scan tool, retrieve TCM DTCs. If DTC P1694 returns, go to next step. If DTC P1694 does not return, go to step 5.
2. Check instrument cluster gauges for proper operation. If fuel gauge and speedometer operate properly, go to next step. If fuel gauge and speedometer do not operate properly, see appropriate INSTRUMENT PANELS article.
3. Turn ignition off. Disconnect Gray PCM harness connector. PCM is located at left front of engine compartment. Disconnect TCM harness connector. Measure resistance of CCD BUS (-) circuit (White/Black wire) between TCM harness connector and Gray PCM harness connector. If resistance is more than 5 ohms, repair open in CCd BUS (-) circuit (White/Black wire). If resistance is 5 ohms or less, go to next step.
4. Measure resistance of CCD BUS (+) circuit (Violet/Brown wire) between TCM harness connector and Gray PCM harness connector. If resistance is more than 5 ohms, repair open in CCd BUS (+) circuit (Violet/Brown wire). If resistance is 5 ohms or less, replace TCM.
5. Conditions necessary to set DTC P1694 are currently not present. Inspect related wiring and harness connectors. See WIRING DIAGRAMS. Repair as necessary. If no problem is found, check for broken, bent, backed-out or corroded terminal pins. Check for chafed, pierced or partially broken wires inside insulation. Repair as necessary.
Last edited:
bert01xj
NAXJA Forum User
- Location
- souderton,pa
Shouldn't my jeep run bad if these codes came up. I mean it runs fine.
Digger87xj
NAXJA Forum User
- Location
- Buffalo Creek/Lakewood CO
Re: Re: three codes is my computer going?
Not necessarily. The LDP has no effect on engine performance.
The PCM and TCM don't need to talk to do their job.
That's the reasoning behind my harness problem suggestion.
Continuity will need to be tested on the CCD bus wires between the two modules.
Another test that requires a scan tool to test the LDP switch and wiring. It can be done manually as well, but more than I want to type out.
Not necessarily. The LDP has no effect on engine performance.
The PCM and TCM don't need to talk to do their job.
That's the reasoning behind my harness problem suggestion.
Continuity will need to be tested on the CCD bus wires between the two modules.
Another test that requires a scan tool to test the LDP switch and wiring. It can be done manually as well, but more than I want to type out.
bert01xj
NAXJA Forum User
- Location
- souderton,pa
Lets now add p1694. I am really feeling like the comp is the problem.
Digger87xj
NAXJA Forum User
- Location
- Buffalo Creek/Lakewood CO
The computer is rarely the problem on XJs.
- Location
- Minneapolis, MN
QFT